Question

Find the height of a square pyramid with volume 243.73 ft3 and dimensions of base are 7.5 ft by 7.5 ft.

A) 13 ft

B) 8.67 ft

C) 4.33 ft

D) 9 ft

Answer 1

@butterflydreamer

Answer 2

do you know the formula for the volume of a square based pyramid? :)

Answer 3

V = a^2 h/3

Answer 4

yep! :)
So in this case, "a" means the length of the base of the pyramid.
So the question tells you a = 7.5
So since we know that you can plug it into the volume formula:
V = a^2 * h/3
So V = (7.5)^2 *h/3
They also told you the volume was 243.73 so plug that into the formula aswell.
243.73 = (7.5)^2 * h/3

Answer 5

alright first. What does (7.5)^2 = ?

Answer 6

Square Pyramid: \[V=a^2\frac{ h }{ 3 }\]
Lets input what we know \[243.73ft^3=7.5^2\frac{ h }{ 3 }\]
So we should work backwards so we start by simplifying the 7.5^squared after that you will divide the answer by 243.73 and get an irrational number which you will multiply by 3 to get the height

Answer 7

h=12.9 ?

Answer 8

Very Close!! its actually 13 xD

Answer 9

Well it'd be h = 12.998
So if we round it up it would be 13 :)

Answer 10

Great Job!

Answer 11

yes thats what i got thanks :)