BCDE is a square. MLD and CLE are straight lines. CB = CM and ∠LCM = 11°. Find
- ∠CBM
- ∠EDM
.
(a)
∠BCE = 45° (Right angle)
∠BCM
= ∠BCE - ∠LCM
= 45° - 11°
= 34°
∠CBM
= (180° - ∠BCM) ÷ 2
= (180° - 34°) ÷ 2
= 146° ÷ 2
= 73° (Isosceles triangle)
(b)
CB = CM = CD
MCD is an isosceles triangle.
∠CMD = ∠CDM (Isosceles triangle)
∠CDM
= (180° - ∠ECD - ∠LCM) ÷ 2
= (180° - 45° -11°) ÷ 2
= 124° ÷ 2
= 62°
∠EDM
= ∠CDE - ∠CDM
= 90° - 62°
= 28°
Answer(s): (a) 73°; (b) 28°
