The dump truck shown has a 15-foot bed length. what is the height of the bed h when angle x is 30, 45, or 60

First, look at my attachment
The dump truck makes imaginary right triangle.

From the right triangle, we can find the h with sin ratio of the triangle. 
h/b = sin of angle
h = b × sin of angle
(h stands for height, b stands for bed)

PART A: If the angle is 45°
h = b × sin 45°
h = 15 × 1/2√2
h = 15 × 0.707
h = 10.607
h = 10.6
The height is approximately 10.6 ft.

PART B: If the angle is 30°
h = b × sin 30°
h = 15 × 1/2
h = 7.5
The height is 7.5 ft.

PART C: If the angle is 60°
h = b × sin 60°
h = 15 × 1/2√3
h = 15 × 0.866
h = 12.990
h = 12.99
The height is approximately 12.99 ft.

What are the options