In the figure, ZCFJ is a rectangle, FGJK is a rhombus and CDEF is a parallelogram. ∠FGJ = 74° and ∠EFG = 91°.
- Find ∠BFC
- Find ∠FED
(a)
∠JKF = ∠JGF = 74°
∠KFJ
= (180° - 74°) ÷ 2
= 106° ÷ 2
= 53° (Isosceles triangle)
∠BFC
= 90° - 53°
= 37°
(b)
∠CFE
= 360° - 91° - 90° - 53°
= 126° (Angles at a point)
∠DEF
= 180° - 126°
= 54° (Interior Angles, CF//DF)
Answer(s): (a) 37°; (b) 54°