







Reinforced steel mesh in a circular foundation 
20150822 

Padmesh pose la question : in a circular foundation we are laying a reinforced steel mesh . i.e., like chords in both ways. the circle diameter is 2.91m and rods are placed 0.1m spacing. so I want to find the number of rods present in that circle. here by I am attaching an auto cad drawing for your reference Penny Nom lui répond. 





The number of possible musical notes using an nkey instrument 
20150504 

Farihin pose la question : Lets say that i have keys, and each key is for notes of a musical instrument,
So i wanted to find out the number of notes i can get for a certain number keys,
of course in the form of an equation. Notes can use as many keys, it can use 1, or 2, or 3, or even 100.
Notes in real life is not as such, but ignore reality.
I tried doing this but i can't seem to find a formula for it.
For example, i have 4 keys, say A, B, C, and D.
so, for notes that uses one key are 4, which is A, B, C, and D themselves.
for notes that uses two keys are 6,
AB, AC, AD, BC, BD and CD.
for notes that uses three keys are 4,
ABC, ABD, ACD and BCD.
lastly for notes that uses all four keys is 1, ABCD.
So, the total will be 4+6+4+1=15#
The nth term for the first equation is n, the second is [(n^2)n]/2
the third and the fourth, i don't know but the final answer should be like,
n + [(n^2)n]/2 + [3rd] + [4th]
Sorry for the long question though... Penny Nom lui répond. 





Two concentric circles 
20150421 

Juniper pose la question : Two concentric circles have radii of 4 cm and 8 cm. A segment is drawn so that it is tangent to the smaller circle and a chord of the larger circle. How long is the segment? Penny Nom lui répond. 





Two chords in a circle 
20140913 

Carlos pose la question : Find the length of the radius of a circle in which a
chord of length 6 units is twice as far from the
center as a chord of length 12 units Penny Nom lui répond. 





Parallel chords 
20140306 

Raj pose la question : AB andCD are two chords which are in the same side of the circle.The length of AB=12 and CD= 24.if the distance between them is 4 then find their radius. Pls help me I just believe on you guys I am having my exam after 3 days p lui répond. 





Two parallel chords of a circle 
20130730 

Don pose la question : two parallel chords of a circle AB and CD on the same side from the center measure 6cm and 11 cm respectively. The distance between the 2 chords is 3 cm. Find the radius Penny Nom lui répond. 





Two parallel chords 
20111204 

violet pose la question : Two parallel chords of a circle AB and CD on the same side of the centre measure 6 cm and 11 cm respectively. Find the radius. Chris Fisher and Walter Whiteley lui répond. 





Two chords in a circle 
20101202 

girma pose la question : one chord of a circle is 8cm long and it's distance from the center is 4cm long.what will be the length of another chord, of the same circle ,which is 2cm from the center Penny Nom lui répond. 





Two perpendicular chords 
20100911 

edwin pose la question : two perpendicular chords AB and CD intersect at P. if X,Y are their midpoints and M the centre of the circle, prove that MP=XY. I do not a have clue on how to do it so can you please help me with it Robert Dawson lui répond. 





Two chords 
20090711 

Sarah pose la question : Two parallel chords in the same circle have lengths of 30 cm and 48 cm. The circle has a radius of 25 cm. How far apart are the chords? Penny Nom lui répond. 





Two chords in a circle 
20090119 

azlaan pose la question : prove that line joining the midpoint of 2 equal chords substain equal angle with the chord? Robert Dawson lui répond. 





One chord is twice as long as another 
20080530 

Stacey pose la question : In a circle, If one chord is twice as long as another, is the longer chord's arc also twice the size of the smaller chord? True or False Chris Fisher lui répond. 





Two chords in a circle 
20070729 

Jerry pose la question : Points A and C lie on the circumference of a circle. B is a point inside the circle. When produced, AB and CB meet the circumference at points E and D respectively. Prove that AB = CB, then EB = BD. Stephen La Rocque lui répond. 





Arcs and chords 
20050109 

Aniesha pose la question : A chord of a circle is 48 centimeters long and is 10 centimeters from the center of the circle. Find the radius? Penny Nom lui répond. 





Two chords 
20031007 

Lori pose la question : Chords AB and CD of circle O intersect at E. If AE=4, AB=5, CE=2, Find ED. Penny Nom lui répond. 





Subdividing a circle 
20021111 

David pose la question : Say you have a cirlcle. Then you draw 2 dots on the circle. Then you connect the dots with lines. The circle is divided into 2 parts. If you do the same with 3 dots and connect each dot to each dot with a line then you get a circle with 4 parts. 4 dots with lines connecting all (6 lines) = 8 parts.... Claude Tardif lui répond. 





Three chords 
20010628 

Paul pose la question : AE is a diameter of a circle and AC, CD and DE are chords of lengths 1, 2 and 3 respectively. (See the diagram.) Find the ridius of the circle. Harley Weston lui répond. 





A parabola problem 
20000323 

Morin pose la question : I need to prove that if parabola x^{2}=4py has a chord (not necessarily a focal chord) intersecting it at points A and B, with tangents to the parabola at points A and B that intersect at C, then a line drawn through C and the midpoint of the chord M is parallel to the yaxis. Further, prove that the point D where this line intersects the parabola is the midpoint of line CM. Penny Nom lui répond. 





The Length of a Chord. 
19970726 

Nathan Arthur pose la question : Picture a 9 inch diameter circle. Inside that circle is a 6 inch diameter circle tangent to it. Then, tangent to both circles is a 3 inch diameter circle. So there are three circles, two smaller ones inside a big one, all of them just touching but not overlapping. Now picture a chord on the 9 inch circle that is created by making a line that is tangent to both the 6 and the 3 inch circles and extending it to the edge of the 9 inch circle. I need the length of that cord. Chris Fisher lui répond. 

