Question

The base of a square pyramid has a side length of 9 inches. The height of the pyramid is 21 inches.

What is the volume of the pyramid?

A.
189 in^3

B.
567 in^3

C.
850.5 in^3

D.
1701 in^3

@DEEISME @iambatman @mathstudent55

Answer 1

Square pyramid's base has 4 equal sides, and the area of the base would be just `side²`.
In this case, `9² → 81`.
The the height is 21 inches, so multiply
21 × 81

••••

Answer 2

btw- if you need help with putting up some symbols (talking to anyone who is viewing or will view this question) I can show you :)

Answer 3

I think I am wrong about the area.

Answer 4

I got the base correctly, but it is a triangle, and will be only using half of the square-height that is 81 inches.

So
21 × 81 × 0.5 would be the answer.

Answer 5

(sorry for this error... well got it fixed now) Good luck :P

Answer 6

i just did that but it doesn't match any of the answers

Answer 7

maybe you plugged some numbers is wrong. I know that, `21 × 81 × 0.5 = 850.5`

OPTION C

Answer 8

@cwrw238

Answer 9

81 × 21 × 1/3 = 567

Answer 10

option B