In the figure, LMNP is a parallelogram. O is the centre of the circle. Find
- ∠LPN
- ∠LMP
(a)
∠OMP = ∠MPO = 25° (Angle properties within a circle)
∠POM
= 180° - 25° - 25°
= 130° (Angles sum of triangle)
∠OLM + ∠OML = ∠MOP (Exterior angle of a triangle)
∠OLM = ∠OML (Isosceles triangle, OL = OM)
∠OLM
= 130° ÷ 2
= 65° (Exterior angle of a triangle)
∠LPN
= 180° - 65°
= 115° (Interior angles)
(b)
∠LMP
= 180° - 65° - 25°
= 90° (Angle sum of triangles)
Answer(s): (a) 115°; (b) 90°