Word problems (help please)

Question

The bottom of a ladder must be placed 20 feet from a wall. The ladder is 29 feet. How far above the ground does the ladder touch the wall?

Answer 1

Using Pythagorean theorem

X ² + y² = Z²

Given X = 20ft , Z = 29ft

Y = ?

(20)² +Y² = (29)²

Y² =( 29)² - (20)²

Y² = 841 - 400

Y = sqrt 441 = 21 ft