PSLE In the figure, KLMN is a parallelogram. HNK and JNM are straight lines and HJ = JK. ∠HJN = 31° and ∠LMN = 56°.
- Find ∠MNK.
- Find ∠NJK.
(a)
∠MNK
= 180° - 56°
= 124° (Interior angles)
(b)
∠HNJ
= ∠MNK
= 124° (Vertically opposite angles)
∠JHN
= 180° - 124° - 31°
= 25° (Angles sum of triangle)
∠JKN = ∠JHN (Isosceles triangle)
∠HJK
= 180° - 25° - 25°
= 130° (Angles sum of triangle)
∠NJK
= 130° - 31°
= 99°
Answer(s): (a) 124°; (b) 99°