Question

A park bench sits 778 feet from the base of the Gateway Arch in St. Louis, Missouri. The angle of elevation from the ground where the park bench sits to the top of the Gateway Arch is 39°.

How tall is the Gateway Arch?


605 feet

630 feet

961 feet

490 feet

Answer 1

• B. 630 ft

Explanation:

Given:

• Horizontal leg of the right triangle = 778 ft
• Angle opposite to vertical length = 39°
• Vertical leg = h

Use tangent to solve for h:

• h/778 = tan 39°
• h / 778 = 0.81
• h = 0.81*778
• h = 630.18

Correct choice is B