SEARCH HOME
 Math Central Quandaries & Queries
 Question from Tina: I have a project where I need to construct a concrete octagonal pad. Each side is 12' and it is 5" deep. Please tell me how to calculate square yards of concrete. Thank you.

Tina,

You can find the area of a regular octagon with sides of length 12' either by looking at our response to Nancy or at our response to Dana. To find the volume in cubic feet you need to multiply buy the height in feet which is $\frac{5}{12}$ feet. There are 3 feet in a yard and hence there are $3 \times 3 \times 3 = 27$ cubic feet in a cubic yard. Hence divide the volume in cubic feet by 27 to find the volume in cubic yards.

Penny

Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.