A 40 foot ladder which is leaning against a wall reaches the wall at a point 36 feet above the ground. Find the measure of the angle created between the ladder and the ground.

Sanderson is having trouble with his assignment. his shown work is as follows: − 3 7 7 3 = − 3 7 × 7 3 = − 21 21 = −1 however, his answer does not match the answer that his teacher gives him. complete the description of sanderson's mistake. find the correct answer.