DEFG is a square. MLF and ELG are straight lines. ED = EM and ∠LEM = 11°. Find
- ∠EDM
- ∠GFM
.
(a)
∠DEG = 45° (Right angle)
∠DEM
= ∠DEG - ∠LEM
= 45° - 11°
= 34°
∠EDM
= (180° - ∠DEM) ÷ 2
= (180° - 34°) ÷ 2
= 146° ÷ 2
= 73° (Isosceles triangle)
(b)
ED = EM = EF
MEF is an isosceles triangle.
∠EMF = ∠EFM (Isosceles triangle)
∠EFM
= (180° - ∠GEF - ∠LEM) ÷ 2
= (180° - 45° -11°) ÷ 2
= 124° ÷ 2
= 62°
∠GFM
= ∠EFG - ∠EFM
= 90° - 62°
= 28°
Answer(s): (a) 73°; (b) 28°
