Need an answer ASAP

Suppose the length of the diagonal of this rectangular television screen is 29 inches and the length of the base of the screen is 21 inches.

2 answers

(height)^2 = (diagonal)^2 - (base)^2

area = (base) * (height)
use the Pythagorean Theorem.
Or recognize one of the basic Pythagorean triples: 20,21,29