Question

3. The angle that can be constructed using ruler and compasses is __________
A.35° B.85° C. 120° D.70°

Answer 1

The angles measuring 15°, 30°, 45°, 60°, 75°, 90°, 105°, 120°, 135°, 150°, 165° and 180°, i.e., all multiples of 15° can be constructed using the ruler and compass.
Since 120 is multiple of 15. Therefore, 120 degree can be constructed using the ruler and compass