2014 · Q51
If from the top of a post a string twice the length of the post is stretched tight to a point on the ground, then what angle will the string make with the post?
Elementary MathematicsTrigonometry
- Aπ/6
- Bπ/4
- C5π/12
- Dπ/3
Explanation
cos(angle) = post/(2 × post) = 1/2, so the angle is π/3.