PSLE Natalie has a triangular piece of paper HJK with JH = JK, ∠HJK = 76° and ∠KLL = 71°. HLK and JLK are straight lines. She folded it along the line LM as shown.
- Find ∠n.
- Find ∠p.
(a)
Length of HJ = Length of JK
Triangle HJK is an isosceles triangle.
∠JKH
= (180° - 76°) ÷ 2
= 104° ÷ 2
= 52° (Isosceles triangle)
∠n
= 180° - 71° - 52°
= 57° (Angles sum of triangle)
(b)
∠JHK = ∠JKH = 52°
∠q
= 180° - 71° - 71°
= 38° (Angles on a straight line)
∠p
= 180° - 52° - 38°
= 90° (Angles sum of triangle)
Answer(s): (a) 57°; (b) 90°