A rectangular piece of paper was folded as shown.
- Find ∠a
- Find ∠f
(a)
∠a
= (180° - 28°) ÷ 2
= 152° ÷ 2
= 76° (Angles on a straight line)
(b)
180° - 76° - 28° = 76° (Interior angles)
∠f
= 360° - 90° - 76° - 76°
= 118° (Sum of angles in a quadrilateral)
Answer(s): (a) 76°; (b) 118°