Question

Medal + fan!
What is the volume of a square pyramid with base edges of 40cm and a slant of height of 29cm?
A 11,200cm^3
B 15,467cm^3
C 16,800cm^3
D 33,600cm^3

Answer 1

I want the answer and how to work it out please, I haven't worked a problem like this before.

Answer 2

@Erak Ideas?

Answer 3

So basically for a pyramid you need V = lwh/3 right? You are given l and w, because a square base with 40cm edges mean l and w = 40.

For the height, you need the center line from the tip of the pyramid to the center of the base. Now try to imagine a right angle triangle, where your slant is the hypotenuse. Just ask and I will draw a bad drawing of this.

So you would get your height by using Pythagoreas

C^2 = A^2 + B^2
29^2 = 20^2 + B^2 <---that side is 20 because it's half of the base
841 = 400 + B^2
B^2 = 841 - 400
B^2 = 441
B = 21 <---your height

Now just do V = lwh/3

Answer 4

AH, I see! Its A correct?

Answer 5

yeah