Question

A 10 meter long wire is attached to the top of a flagpole 5√3 meters long. What is the measure of the angle the wire makes with the ground?

A. 25 degrees
B. 45 degrees
C. 60 degrees
D. 90 degrees

Answer 1

Well there has to be a right angle in there somewhere as the pole must be perpendicular to the ground.

Using the sine rule:
sinA/a = sinB/b where a = 10, A = 90, b = 5√3, B = B
Re-arrange for B, B = arcsin (b(sinA)/a)
B = arcsin(5√3(sin90)/10)
B = 60 degrees.

Answer is C