In the figure, BCDE is a parallelogram. DG, GH and BC are straight lines. BEF is an isosceles triangle.
- Find ∠m.
- Find ∠n.
(a)
∠DGB = ∠CBH = 64° (Corresponding angles, BC//GD)
∠GFB
= 180° - ∠DGB - ∠GBF
= 180° - 64° - 21°
= 95° (Angles sum of triangle)
∠EFB
= 180° - 95°
= 85° (Angles on a straight line)
∠FEB = ∠EFB = 85° (Isosceles triangle)
∠m
= ∠FEB
= 85° (Corresponding angles, CD//BE)
(b)
∠n
= 180° - 85° - 85°
= 10° (Isosceles triangle BEF)
Answer(s): (a) 85°; (b) 10°