A tree 6 m tall casts a shadow 6√3 m long. What is the angle of elevation of the top of the tree?

Think it through first, then pick an option.

Answer and explanation

Correct answer: b 30°

tan θ = 6/(6√3) = 1/√3 = tan 30°, so θ = 30°.

Why the other options are wrong

a 0°: 0° is impossible for a tree of height 6; tan θ = 6/6√3 = 1/√3 gives θ = 30°.
c 45°: At 45° the shadow would be 6 m; here it is 6√3, much longer.
d 60°: At 60° the shadow would be 6/√3, shorter than the height; here it is longer.