JKLM is a square. MLL and KLM are straight lines. KJ = KM and ∠LKM = 11°. Find
- ∠KJM
- ∠MLM
.
(a)
∠JKM = 45° (Right angle)
∠JKM
= ∠JKM - ∠LKM
= 45° - 11°
= 34°
∠KJM
= (180° - ∠JKM) ÷ 2
= (180° - 34°) ÷ 2
= 146° ÷ 2
= 73° (Isosceles triangle)
(b)
KJ = KM = KL
MKL is an isosceles triangle.
∠KML = ∠KLM (Isosceles triangle)
∠KLM
= (180° - ∠MKL - ∠LKM) ÷ 2
= (180° - 45° -11°) ÷ 2
= 124° ÷ 2
= 62°
∠MLM
= ∠KLM - ∠KLM
= 90° - 62°
= 28°
Answer(s): (a) 73°; (b) 28°
