The figure is not drawn to scale. BDEF is a trapezium and BD // FE. Given that BF = BC, ∠FBC = 73° and ∠BDE = 97°.
- Find ∠DEF
- Find ∠BCF
- Find ∠CFE
(a)
∠DEF
= 180° - 97°
= 83° (Interior angles, BD//FE)
(b)
∠BCF
= (180° - 73°) ÷ 2
= 107° ÷ 2
= 53.5° (Isosceles triangle)
(c)
∠CFE
= ∠BCF
= 53.5° (Alternate angles, BD//FE)
Answer(s): (a) 83°; (b) 53.5°; (c) 53.5°