Answer: d
Step-by-step explanation:
Note that the distance to the tower and the height of the tower create a right triangle at the base of the tower. The equation to find the height of a right triangle is to multiply the length times the tangent of angle β.
Given:
b = a · tanβ
tan(30°) = √3/3
Step 1: Solve
b = (30/1) · (√3/3)
b = (30 · √3) / (1 · 3)
b = (30√3) / (3)
b = 10√3