### Home > CALC > Chapter 12 > Lesson 12.1.3 > Problem 12-39

12-39.

First, determine when the ball hits the ground. This is when *y*(*t*) = 0.

Then angle is the angle created by the slope.

Think of drawing a slope triangle and calculating the angle.

12-39.

First, determine when the ball hits the ground. This is when *y*(*t*) = 0.

Then angle is the angle created by the slope.

Think of drawing a slope triangle and calculating the angle.