







Two concentric circles 
20161221 

shrestha pose la question : Two concentric circles have radii of 14 cm and 7 cm respectively. Find the area of space between them. Penny Nom lui répond. 





The area of the ring between two concentric circles 
20150408 

Conner pose la question : The area of the ring between two concentric circles is 25pi/2 square inches. The length of a chord of the larger circle tangent to the smaller circle is? Robert Dawson lui répond. 





A path around a pond 
20091031 

adeniji pose la question : find the area of a concrete path 2m wide surrounding a circular pond 12m in diameter Penny Nom 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. 





Annular sector 
20090720 

Ed pose la question : What is the name for the section of a flat ring (annulus)? Similar to a section on a radar screen, a quadrilateral but the top and bottom are curved. Robert Dawson lui répond. 





The diameter of a roll of plastic 
20090324 

truong pose la question : hi. i have trouble to calculate the diameter of the plastic roll. the sheet is 765 m long and 0.8 mm to wrap around the core 400 mm in dia. please help me with the formula to calculate the dia of plastic roll, thanks in advance Harley Weston lui répond. 





The region between two circles 
20080924 

Carol pose la question : Good day!
Here is a picture of the problem that we need to solve. (I send the picture through email.)
A small circle is inside a larger circle, the only given in the problem is the chord of the larger circle tangent to the smaller circle which measures 16cm. The question is, what is the area of the shaded region?
Can you answer this question? Thanks! :) Harley Weston lui répond. 





Two circles 
20080610 

cey pose la question : the diameter of the larger circle is 20cm, and the smaller 10cm. what is the shaded area?? Janice Cotcher lui répond. 





The area of a circle knowing only the length of a chord 
20070905 

James pose la question : I need some help in the right directions with a problem. I was presented with a problem where I need to find the area of a circle knowing only the length of a chord.
the is a circle in the center of a larger circle (which the size of either could change) the only thing that matter is that the chord is 100 ft long and rests on top of the smaller circle. Stephen la Rocque and Brennan Yaremko lui répond. 





Pattern for a truncated cone 
20070511 

Mike pose la question : I have been trying to get this cone flat so I can build this column. Can you please help me so I can figure this out? Thanks for your help. Stephen La Rocque lui répond. 





Edging surrounding a round pool 
20070503 

Carol pose la question : Hello,
I am new at this and very rusty on my math. I am getting a 24 Ft. round pool and would like to put 2ft width stone (small) edging around it. How much would I need to buy. I have to buy it by the yard (cubic yard) I am not looking for an exact, just an approx. even would be great.
Thanks
Carol Stephen La Rocque lui répond. 





Two concentric circles form an annulus 
20070502 

A student pose la question : In the diagram below, two concentric circles form an annulus. The
vertical line is tangent to the inner circle, and forms the diameter of
a third circle.
Explain why the areas of the annulus and third circle are the same. Penny Nom lui répond. 





Area of an annulus 
19960404 

Ryan Levering pose la question : What is the area of this annulus? Penny Nom lui répond. 

