In the figure, BCF and ECD are right-angled triangles. FC is parallel to ED. Find
- ∠CDE
- ∠CFE
(a)
∠ECF
= 360° - 90° - 90° - 121°
= 59° (Angles at a point)
∠CED = ∠ECF = 59° (Alternate angles)
∠CDE
= 180° - ∠ECD - ∠CED
= 180° - 90° - 59°
= 31° (Angles sum of triangle)
(b)
∠CFE
= 180° - ∠ECF - ∠CEF
= 180° - 59° - 82°
= 39° (Angles sum of triangle)
Answer(s): (a) 31°; (b) 39°