Two square pyramids have the same volume. the first pyramid has base edge 20 in. and height 21 in. the second pyramid has height 84 in. what is the base edge of the second pyramid? 28 in. 10 in. 21 in. 42 in

By definition, the volume of a square-based pyramid is given by:

Where,

Ab: base area

h: height

Substituting values for the first pyramid we have:

Then, for the second pyramid, since the volume is the same, then we must clear the length of the base.

We have then:

Substituting values:

The base edge of the second pyramid is:

10 in

first, you divide the triangle in two, tô form a retangle triangle. after, using pythagoream theorem:

18^2 = 14^2 + (x/2)^2

(x^2/4) + 196 = 324

x^2/4 = 324 - 196

x^2/4 = 128

x^2 = 512

x = √512

x = √2^9

x = 16√2 cm

i hope i you.