







A cone formed from a circular sector 
20180418 

Jessica pose la question : A circle has a radius of 7.5cm. A sector with an angle of 240 degrees is cut out from the sector. If the sector is folded to form a cone. Find the length of the cone. Penny Nom lui répond. 





An arched window 
20170724 

Gerry pose la question : Looking to make a full size template for an arched window. Need increments every 16". The radius is 138' 0 9/16" , the chord is 226" and the rise at center of chord is 43" Penny Nom lui répond. 





The volume of a slab 
20170121 

Russell pose la question : Working with a segment of a circle. The O.D. is 3.440" the length of the chord is 3.130 I need information on the volume of the largest area. I would like to know (in thousands of an inch) how tall would the largest area need to be to equal .1143 cubic inches If you need more info I can send it Thanks in advance p lui répond. 





Heights at various points along an arc 
20160415 

Isiah pose la question : So I am working on a problem with a few friends; you have an arc with the center of its chord at 0,0. We also have a known sagitta and a known radius of curvature.
How do we calculate the height extending in both the positive and negative directions?
Central sag: 2.48
Chord length: 9.6 Penny Nom lui répond. 





Archimedes, Euclid and "Circular Reasoning" 
20151115 

Ron pose la question : I have read about Archimedes and his work with sphere in cylinder and cone in cylinder and the volume relationships. Did he or any others also extend this to regular based polygon based regular like pillars, and columns? The ratio of 1/3 to 1 whole holds true with all regular based columns as example: a regular pyramid having a regular hexagon base inside a regular hexagon column of equal height. Chris Fisher lui répond. 





The area of a domed roof 
20151113 

Brandon pose la question : I have a tank with a 13' radius that has a domed roof of 3.5' tall How do I figure out the area in SQFT? Penny Nom lui répond. 





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 surface area of a round bar 
20150606 

chirag pose la question : Please tell me the formula for finding round bar surface in square inches/ mm Penny Nom lui répond. 





A parallelogram inscribed in a circle 
20150204 

narendra pose la question : how can we prove that a circular parallelogram is a rectangle? Chris Fisher lui répond. 





The surface area of a circular dome 
20140410 

Shafiqah pose la question : Is this a dome's surface area formula??
{{2 × π r × h square units}}
Is the surface area of the floor for the dome is calculate too in this formula?
Thanks for answering. =) Robert Dawson and Penny Nom lui répond. 





Can a cylinder be considered a circular prism? 
20140208 

Davina pose la question : Can a cylinder be considered a circular prism? Penny Nom lui répond. 





A square inscribed in a circle 
20131014 

Jenn pose la question : Hello! I am about to buy a 7'9" round rug, but I want to have it cut down into a square. What's the largest square I can obtain from this? Thank you! Penny Nom lui répond. 





A semicircular roof gutter 
20120409 

Kyle pose la question : A semicircular roof guttering contains some water.
The crosssection of the guttering has a diameter of 10 centimetres. The surface of the water collected in the guttering is 8cm.
What is the depth of water in the gutter? Penny Nom lui répond. 





A man made circular lake 
20101125 

ailish pose la question : A man made circular lake has a diameter of 338 m. A bridge is to be constructed across the lake in such a way that it is 119 m away from the center of the lake. How long is the bridge? Penny Nom lui répond. 





May Lee's cake 
20100918 

Wafa pose la question : May Lee bought a cake which is circular in shape. Her sister ate a quarter of the cake. Given that the area of the top surface of the remaining portion is 520 square cm, find the diameter of the cake. Penny Nom lui répond. 





Two cars on a circular track 
20100812 

david pose la question : If two cars starts to drive at point 1 and go in a circle when will they meet?
(one cars speed is faster the other ) all I need is a formula Tyler Wood lui répond. 





A pile of sand 
20091216 

Malik pose la question : Sand is leaking out of a hole at the bottom of a container at a rate of 90cm3/min. As it leaks out, it forms a pile in the shape of a right circular cone whose base is 30cm below the bottom of the container. The base radius is increasing at a rate of 6mm/min. If, at the instant that 600cm3 have leaked out, the radius is 12cm, find the amount of leakage when the pile touches the bottom of the container. Harley Weston lui répond. 





A circular border around a pool 
20090908 

Calvin pose la question : A pool in the shape of a circle measures 10 feet across. One cubic yard of concrete is to be used to create a circular border of uniform width around the pool. If the border is to have a depth of 3 inches, how wide will the border be? ( 1 cubic yard=27 cubic feet ) Stephen La Rocque lui répond. 





4 couples seating themselves at a round table 
20090904 

Hui pose la question : Q: 4 couples seating themselves at a round table. Men must seat together and women seat together. How many ways are there? Answer in the printed text is 576. I got 144. Pls advice. Claude Tardif lui répond. 





The surface area of a tank 
20090625 

Charles pose la question : I need to calculate the external wall and top sqft surface area of a tank 54ft od x 15ft high with a dome top 54ft od x 8ft high. Penny Nom lui répond. 





A semi circular room 
20090211 

Taylor pose la question : being 450pi (the area of a semi circle)
how much money would it cost to lay carpet at $2.57 per foot???
if the area of a semi circular room is 450 pi ft
then what is the volume being that the diameter is 60 feet
and the ceiling is 16 feet tall Robert Dawson and Penny Nom lui répond. 





Seating around a circular table 
20090209 

Jenny pose la question : A committee of 15  9 women and 6 men  is to be seated at a circular table (with 15 seats). In how many ways can the seats be assigned so that no two men are seated next to each other? Victoria West lui répond. 





Three circular rings 
20081218 

seema pose la question : three circular rings of equal radii of 1cm each are touching each other.
a string runs all around the set of rings very tightly. what is the minimum length
of string required to bind all the three rings ? Robert Dawson lui répond. 





Jogging around a circular track 
20081119 

kim pose la question : Joan wants to jog 10 miles on a circular track 1/4 miles in diameter. How many times must she circle the track? Penny Nom lui répond. 





The volume of fluid in a semi circular trough 
20081010 

Kerry pose la question : How do I find the volume of fluid in a semi circular trough? Penny Nom lui répond. 





A bowl is the shape of a hemisphere 
20080428 

josh pose la question : a bowl is the shape of a hemisphere with diameter 30 cm and water is poured into the bowl to a height h cm. how do i find the volume of the water in the bowl Harley Weston lui répond. 





The radius of a circular arc 
20080204 

Bill pose la question : Hi,the Central Angle of a sector of a circle is 40 degrees. The circular arc of the curve has a chord length of 3000 ft. Find the radius(r) of the circular arc. Penny Nom lui répond. 





A large concrete shape 
20080116 

Keith pose la question : what is the cubic yards of an area that is not a perfect 1/4 circle?
The dimensions are 100ft. x 60ft. x 125ft. curcumferal arch x 3ft. depth? Stephen La Rocque lui répond. 





An arched entry 
20071128 

amber pose la question : i am working with an arched entry. i know that the radius is 25' and the height is 20'11". i need to know the length of the arch and degree of bend of the arch. how do i find these? Stephen La Rocque lui répond. 





A circular table is pushed into the corner 
20071031 

Will pose la question : A circular table is pushed into the corner of a square room so that one point is 8 inches from one wall and 9 inches from the other. What is the radius of the table? Penny Nom lui répond. 





A cylindrical slab of concrete 
20070630 

Kenn pose la question : I have a tank that needs a base of cement put in it. I dont know how to do this. The tank is 8 feet across and I want the cement to be 5 or 6 inches deep. Can you please tell me how much cement I need to do this. Harley Weston lui répond. 





Water tank volume 
20070529 

Cecelia pose la question : I HAVE A SEMI CIRCULAR TANK AGAINST A WALL MEASURING 6'10" ACROSS THE WIDEST PART AND 3' FROM THE WALL TO THE FRONT OF THE TANK. THE DEPTH IS 14". PLEASE HELP ME TO CALCULATE THE VOLUME OF WATER IN THE TANK. Stephen La Rocque lui répond. 





Constructing an octagonal deck around a circular pool 
20070420 

Cliff pose la question : [I am building an] octagonal desk encompassing 17 foot diameter circle for pool.
I have seen other octagonal calculations but none of these tell me how much allowance for a circle to fit within the octagon without losing the circle edge can anyone help
thanks cliff Stephen La Rocque lui répond. 





How many feet tall is the tunnel 
20061014 

Charles pose la question : A tunnel in the Smoky Mountains is semicircular. At a distance of 12 feet from the center of the tunnel, the tunnel has a height of 16 feet. How many feet tall is the tunnel at its center? Penny Nom lui répond. 





Gallons of water in a well 
20060731 

Martha pose la question : I have a shallow water well that is 30 feet in depth.
I have 8 feet of water in the well.
The water well is a 30 inch in diameter.
My question : How many gallons of water is in my tank? Penny Nom lui répond. 





A cone with vertex (1,1,2) 
20050926 

Brandon pose la question : Find the equation of a double cone with vertex (1,1,2) and which intersects the xy plane in a circle of radius 4. Penny Nom lui répond. 





A seating arrangement 
20050203 

Kay pose la question : If you have 5 married couples, how many arrangements can be made if they must sit across from each other? Penny Nom lui répond. 





A line from the center of the patch to the periphery 
20050101 

Sandrine pose la question : I am currently researching a patch disease of grasses. These patches are roughly circular. I need a term for a line from the center of the patch to the periphery. Since the patches are not perfectly circular, my supervisors tell me I cannot use the word 'radius'. What else could I use? Denis Hanson and Harley Weston lui répond. 





Volume of a fuel tank 
20040301 

Mike pose la question : I have a fuel ank for my big truck that has a radius of 24inches and a length of 65 inches. I am trying to compute the volume of fuel in the tank. I tried pie x the radius squared times the length but no usable results.
Can you help me please? Penny Nom lui répond. 





Volume of a tube 
20040114 

Mike pose la question : where can you find how to get volume of a tube:
3 in across x 3 inch high
5 in across x 5 inch high
same formula for both. ONE will get the other. Penny Nom lui répond. 





Arrangements around a circular table 
20031007 

Lori pose la question : How many arrangements can 6 people be seated round a circular table? Penny Nom lui répond. 





The volume of water in a hose 
20021113 

David pose la question : I trying to find out how much water 500 ft of 3/4 inch hose will hold. I'd also like to know how you figured the answer. Penny Nom lui répond. 





A circular wading pool 
20020304 

Patrick pose la question : The community of melfort is planning to build a circular wading pool in the park. The pool will cover an area of 1000m^{2}. The building committee has decided to put a 5m cement pad around it. How much additional area will the cement pad take up? Harley Weston lui répond. 





Building a circular silo 
20010124 

Natasha pose la question : We wish to build a circular silo with internal diameter 10 feet. How much concrete will we need to pour the foundation, if we only need a 1 foot wide and 1 foot deep ring on which the silo walls will sit? Assume the 4 inch thick silo wall rests on the middle of the ring. Penny Nom lui répond. 





Circular Permutations 
20000918 

J. Stuart pose la question : I am able to understand the simple theory behind circular permutations (that is, there are (n1)! ways to arrange n people in a circle. One question, however, is giving me some difficulty. It reads: In how many ways can four married couples be arranged around a circular table if each man must sit beside his wife? Any suggestions you have would be greatly appreaciated. Penny Nom lui répond. 





Trolls and Gargoyles 
19991102 

TexGrimm pose la question : How can you seat 6 monsters  3 Trolls and 3 Gargoyles at a circular table if the trolls look alike and the gargoyles look alike? Does your formula work for 9 monsters  4 trolls and 5 gargoyles? Penny Nom lui répond. 





Circular Permutations 
19970205 

Ed Varjassy pose la question : I have an understanding of simple problems involving circular permutations but do not understand them when they start to have restrictions. Is there any advice you can give for these more complicated permutations. Penny Nom lui répond. 

