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law of cosines

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50 articles trouvés pour ce sujet.
 
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A triangular garden 2020-05-24
yoonji pose la question :
the 3 sides of a triangular garden measure 200 ft., 250 ft., and 300 ft., respectively. the garden is to be divided by a line bisecting the longest side and drawn from the opposite vertex. what is the length of the bisecting line?
Penny Nom lui répond.
An angle i a triangle 2020-05-16
Ogunjobi pose la question :
Two goal post are 8m apart a footballer is 34 m from one post and 38m from the other within what angle must he kick the ball if he is to score
Penny Nom lui répond.
A footballer angle 2018-02-14
Kim pose la question :
Two goal posts are 8m apart. A footballer is 34m from one post and 38m from the other. Within what angle must he kick the ball if he is to score a goal.
Penny Nom lui répond.
How far apart are the boats? 2016-12-13
Halley pose la question :
Two boats leave port at the same time. Boat A travels east at a speed of 12 km/hr. Boat B travels southwest at a speed of 14 km/hr. After two hours, how far apart are the boats? North is 0 degrees. How do I figure this out. Thanks
Penny Nom lui répond.
Two airplanes 2015-04-14
john pose la question :
two planes leave an airport at the same time, one going northwest (N35*W)at 400 mph and the other going east at 332 mph. How far apart are the planes after 4 hours to the nearest mile?
Penny Nom lui répond.
A triangular chicken pen 2014-04-27
Cierra pose la question :
Margaret has two lengths of fence, 20 meters and 24 meters, for two sides of a triangular chicken pen. The third side will be on the north side of the barn. One fence length makes a 75° angle with the barn. How many different pens can she build if one fence is attached at the corner of the barn? What are all the possible lengths for the barn side of the pen?

Not sure what they are asking here... please show step by step what to do! Thank you so much!

Penny Nom lui répond.
The sides of a triangle 2014-04-06
Michael pose la question :
I am supposed to sove for the length of side "b" of an irregular triangle. I am given the following:
Side a: 65'
Side b: Find this length
Side c: 50'
Angle A: unknown
Angle B: unknown
Angle C: 52 degrees
I am supposed to use the law of cosines to solve for side "b" and my teacher says there is no mistake in the "givens" for the problem. I do not see how this can be done using the law of cosines and i have not figured out how to sove for angle B to use the law of cosines.

Penny Nom lui répond.
A triangle problem 2013-10-02
raneem pose la question :
ABC is a triangle in which : BC=20cm. M(<B) =29 and m(<C)=73 . D is the midpoint of BC Find the length Of AB and AD approximated to 2 decimal places
Penny Nom lui répond.
The fourth side of an irregular polygon 2013-02-01
Emran pose la question :
I have a irregular polygon. I know 3 of the 4 sides, and 2 of the angles. A-B is 285, B-C is 149, and C-D is 310. Angle B is 135 degrees. and Angle C is 45 degrees. Is there a formula to solve for the final side? Thanks.
Penny Nom lui répond.
Three sides of a triangle 2011-12-24
saba pose la question :
the three sides of a triangular lot have lengths 10,11and 13cm,respectively. find the measure of its largest angle and the area of the lot?
Penny Nom lui répond.
How far must the pitcher travel to get to the ball? 2010-11-04
ken pose la question :
A baseball player bunts a ball down the first base line. It rolls 35ft at an angle of 26 degrees with the first base path. The pitchers mound is 60.5 ft from the plate. How far must he travel to get to the ball.
Penny Nom lui répond.
A radio tower 2010-03-26
Alex pose la question :
The height of a radio tower is 450 feet, and the ground on one side of the tower slopes upward at an angle of 10 degrees. How long should a guy wire be if it is to connect to the top of the tower and be secured at a point on the sloped side 110 feet from the base of the tower?
Harley Weston lui répond.
A quadrilateral with 4 known sides and 1 known angle 2010-03-19
samuel pose la question :
Name: Samuel
Status: Student

I have a quadrilateral with 4 known sides and 1 known angle, and I'm trying to evaluate the other angles of my quadrilateral.

By the law of cosines, I can easily find my opposite angle (using the diagonal as a basis for the equation).

However, to find the two remaining angles, I have found no other way so far than to use the other diagonal, which can be found with the equation attached (from geometry atlas).

Is there any simpler way?

Robert Dawson and Harley Weston lui répond.
Solving a triangle 2010-01-25
Paige pose la question :
how do i solve a triangle with one angle of 73 degrees, one angle of 32 degrees, and one side of 23cm?
Harley Weston lui répond.
A trig question 2009-12-15
A trig question pose la question :
Hey, my name is Candle
I'm in academic math10 and am stuck on my trig... one question I thought I had right because i used the cosine law I got wrong and can't figure out why... here's a copy of the question. (i guessed it was D... but my teacher said it's B)
Thanks
Candle

Robert Dawson lui répond.
How fast is the distance between the two cars decreasing? 2009-12-08
Jenny pose la question :
Two cares are on a collision course toward point P. The paths of the two cars make a 30 degree angle with each other. The first car is 40 km from P, and traveling toward P at 16 km/hour. The second car is 50 km from P, traveling at 20 km/hour. How fast is the (straight line) distance between the two cars decreasing. (Hint: Law of Cosines)
Harley Weston lui répond.
Related rates 2009-03-09
Megan pose la question :
A plane flying with a constant speed of 330 km/h passes over a ground radar station at an altitude of 3 km and climbs at an angle of 30°. At what rate is the distance from the plane to the radar station increasing a minute later?
Harley Weston lui répond.
Find the resultant of this displacement pair 2009-02-22
katydidit pose la question :
Find the resultant of this displacement pair:
500 miles at 75 degrees east of north and 1500 miles at 20 degrees west of south.
How do I graph this and how do I solve this problem?

Penny Nom lui répond.
The angle between two lines 2008-12-17
abhi pose la question :
how to calculate the angle between two lines, given the length of the lines.. angle should vary from 0 - 360 in the counterclockwise direction
Robert Dawson and Harley Weston lui répond.
The path of a small sailboat 2008-11-19
jane pose la question :
a sailor in a small sailboat encounters shifting winds. she sails 2.00 km East then 3.40 km North East, then an additional distance in an unknown direction. Her final position is 6.68 km directly east of the starting point. find the magnitude & direction of the third leg of the voyage.
Harley Weston lui répond.
How far are the boats apart? 2008-11-14
dom pose la question :
Two boats leave port at the same time. They leave at 150 degree angle. One boat travels at 10mph and the other at 20mph. After two hours how far are the boats apart?
Penny Nom lui répond.
The angles and sides of a triangle 2008-11-13
JAMIE pose la question :
a triangle with a side(b)37m an angle(C)70degrees and (a)79m find values of angles A and B and length of side c
Stephen La Rocque lui répond.
Guy wires for a tower 2008-05-19
larissa pose la question :
a radio tower 500 feet high is located on the side of a hill ( the hill has an inclination to the horizontal of 5 degrees.) How long should two guy wires be if they are connected to the top of the tower and are secured at two points 100 feet directly above ( up the hill ) and directly below the base of the tower?
Penny Nom lui répond.
The length of the third side of a triangle 2008-02-16
mary pose la question :
I have an angle of 72 degrees and each of the sides are 5' long. What is the distance from each of the ends of the 5 feet to form a triangle.
Stephen La Rocque lui répond.
The angles of a triangle given the three sides 2008-01-17
Lucy pose la question :
Is there a way to find the angles of a triangle just by knowing the lengths of it's sides? It seems like the would be a relationship between the two, but I'm not sure.
Stephen La Rocque and Harley Weston lui répond.
How far is the jet from the lighthouse? 2008-01-07
Natalie pose la question :
Question: A ship spots a lighthouse that is 53m high, at an angle of elevation of 7 degrees that is directly north of the ship. The same ship spots a jet travelling N62E at an altitude of 1500m with an angle of elevation of 15 degrees. How far is the jet from the lighthouse?

Natalie

Harley Weston lui répond.
Area of a quadrilateral 2007-10-10
Courtney pose la question :
how would i find the area of a quadrilateral..
the sides are a (/) is 6cm, b (—) is 9 cm, and c (\) is 7 cm..
the angle between a and b is 140 degrees and b and c is 115 degrees..

Stephen La Rocque lui répond.
The length of the third side of a triangle 2007-08-15
Brooklyn pose la question :
What is the equation to find the length of the third side of a triangle if you have the length of A, B, and the angles(s)?
Stephen La Rocque lui répond.
Calculating the area (acreage) of a four sided lot 2007-07-18
A property owner pose la question :
I have a real estate property and the lot size is something I need to find out. I know the lengths of the four sides, but it isn't a rectangle, it is an odd shape. How do I find the acreage?
Stephen La Rocque lui répond.
Any regular polygon inscribed in a circle 2007-07-12
DJ pose la question :
Circle with r=12" is inscribed in a regular octagon. What is the length of each octagon segment? Note: Our answer works for any regular polygon inscribed in any circle.
Stephen La Rocque lui répond.
The area of a quadrilateral 2007-06-10
Lucy pose la question :
Calculate the area of the quadrilateral ABCD. AB= 4.1cm, BC = 7.6cm, AD= 5.4 cm, CD= ? Angle ABC = 117, Angle ADC = 62. Give your answer correct to 3 significant figures.
Stephen La Rocque and Penny Nom lui répond.
The law of cosines 2007-03-23
chetna pose la question :
Q 1) In triangle LMN, l=7, m=5 , n=4. find ANGLE N. After applying the rule and substituting values i'm getting Cos n= 58/40. Is there something wrong. The answer at the back of the book is 34 degrees.
Penny Nom lui répond.
A trig problem 2006-06-24
Greg pose la question :
A and B are two towers, B being 4 km due east of A. The true bearings of a flagpole, C, from A and B are α east of north and α west of north respectively. The true bearings of a second flagpole, D, from A and B are (α + β) east of north and (α - β) west of north respectively. Assuming A, B, C, and D are on level ground, and that α = 25, β = 10, find the distance between C and D.
Penny Nom lui répond.
The chord length of a polygon 2006-06-14
Krishna pose la question :
I have to find out the chord length of a polygon - Tetradecagon ! The Radius of the Circle is 11.5 Cms. The Circle is intersepted by 14 arcs. Then how to find out the chord length?
Stephen La Rocque lui répond.
Three towns are located at the vertices of an equilateral triangle 2006-03-20
A student pose la question :
three towns are located at the vertices of an equilateral triangle. The towns are 8, 5, and 3 miles, respectively, from a store. How far apart are the towns?
Chris Fisher lui répond.
How do you find the angles in a triangle? 2006-01-27
Keith pose la question :
How do you find the angles in a triangle if you know the lengths of the sides?
Chris Fisher and Penny Nom lui répond.
Solving triangles 2004-10-30
Allen pose la question :
Solve the following triangles.

Given

1. B = 20 Degrees, a = 25, b = 16
2. A = 35 Degrees, b = 2, c = 3
3. A = 32 Degrees, C = 44, c = 20

Harley Weston lui répond.
Finding bearings 2004-05-24
James pose la question :
This question is about finding bearings. A boat race starts from point A, goes North to Point B, a distance of 1000 meters. The course is triangular. The bearing from point B to point C is South 70degrees West. The distance from Point B to point C is 1500 meters. Find the course bearing from C to A.
Penny Nom lui répond.
Laws of sines and cosines 2003-11-23
A parent pose la question :
On the one side of a stream lines PA= 586.3 feet, PB = 751.6 feet are measures, angle APB being 167 degrees and 36 min. Q is a point on the opposite side of the stream. Angle PAQ=63 degress and 18 min and PBQ=49 degrees and 24 min. Find PQ.
Penny Nom lui répond.
Two trig problems 2003-06-10
Bett pose la question :

I have this ongoing trouble with trig and solving triangles with laws of cosines and sines!! For example if it asks to solve triangle FGH, given angle G=102.7 , side f=14.2, and h=18.6. Now do I use law of cosines because I don't have the measure of an angle and length of the opposite side??I don't know where to go from here,I am totally confused!!!

I also have a problem with this word problem I have been doing. It asks: An airplane flies 847.5 km at a bearing of 237.3 degrees. How far south and west fo its original position is it? Huh? Please help!


Penny Nom lui répond.
How far apart are the transmitters? 2002-05-18
Jeff pose la question :
A ship at sea is 70 miles from one transmitter and 130 miles from another. The measurement of the angle between the signals is 130 degrees. How far apart are the transmitters?
Penny Nom lui répond.
The law of cosines and obtuse angles 2002-05-09
Bryant pose la question :
The question that I am pondering is that I need to derive the law of cosines for a case in which angle C is an obtuse angle.
Penny Nom lui répond.
Adding vectors 2002-01-12
Lena pose la question :
how do you add vectors together?
If you are given the length and angles of both vectors and are asked to add/subtract them, how do you do it? I know you are supposed to do the head to tail method, but whenever i try it i get the wrong answer. I need help setting it up.

example: A is 2.7cm, and 60 degrees, B is 1.6cm and 135 degrees, find the magnitude and amplitude


Penny Nom lui répond.
The speed of the boat 2001-07-12
Sharon pose la question :
A motor boat is travelling in a southeasterly direction in water that is flowing from the south at 2km per hour. Show that the speed of the boat is (6 times the square root of 2) km per hour, given that it can travel at 10km per hour in still water.
Penny Nom lui répond.
The angles in a triangle 2001-05-11
Nikki pose la question :
Find the measure, to the nearest degree, of each angle of a triangle with sides of the given lengths.

26, 35, 40


Penny Nom lui répond.
The law of cosines in the real world 2001-02-21
Hope pose la question :
Do you have any examles and/or labs that show how the law of cosines is used in the real world?
Harley Weston lui répond.
Law of cosines 2001-02-20
Emily pose la question :
I missed a few days of class and I can't figure out how to solve Law of Cosines problems. I have the notes and formulas but I can't figure out how to do the math involved to answer the problems. I am also getting confused about how to use degrees and seconds in the Law of Sine and Cosine. I can't seem to get the correct answers and I don't really know how to solve them and enter them into my TI 86.
Harley Weston lui répond.
The laws of sines and cosines 2001-01-02
Faydene pose la question :
Can the sine /cosine rule be applied to a right -angle triangle to find a particular solution or are these 'rules' applied only when the triangle is not right angled?
Penny Nom lui répond.
From an airport control tower 1999-08-04
Pammy pose la question :
Hi I am a 30 yo mature age student doing my HSC but am having difficulty understanding this, if you can help me.

From an airport control tower, a Cessna bears 023 degrees T and is 27km away. At the same time, a Boeing 767 bears 051 degrees T and is 61km from the tower. Both planes are at the same height.

i) What is the size of angle ATB?

ii) Using the cosine rule to calculate the distance the planes are apart, to nearest kilometre.

I figured out and drew the triangular diagram but can't figure out the rest and which formula to use. sorry about this, thankyou kindly
Harley Weston lui répond.

Ajax, Beverley, Canton and Dilltown 1997-03-14
S. Johnson pose la question :
The following towns are placed on a coordinate system. Ajax at (-x,z), Dilltown at (-10,0), Canton at (0,0) and Beverly at (0,10). The roads from Beverly to Canton and from Canton to Dilltown are perpendiculat to each other and are each 10 miles in length. A car traveling at all times at a constant rate, would take 30 minutes to travel straight from Ajax to Canton, 35 minutes to travel from Ajax to Canton via Beverly, and 40 minutes to travel from Ajax to Canton via Dilltown. What is the constant rate of the car, to the nearest tenth of a mile per hour.
Chris Fisher and Harley Weston lui répond.
 
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