Let
l-------> the slant height of the right pyramid
b------> the length side of the square base of the right pyramid
h------> the height of the right pyramid
we know that
Applying the Pythagorean Theorem
\(l^{2} =h^{2}+(\frac{b}{2})^{2}\)
Solve for h
\(h^{2}=l^{2}-(\frac{b}{2})^{2}\)
in this problem we have
\(l=20\ ft\\\frac{b}{2} =\frac{24}{2} =12\ ft\)
Substitute in the formula
\(h^{2}=20^{2}-12^{2}\)
\(h^{2}=256\)
\(h=16\ ft\)
therefore
the answer is
The height of the right pyramid is \(16\ ft\)
