In the figure, not drawn to scale. GHJK is a square. JKL is an equilateral triangle and GJ is a straight line. Find
- Two-fifths of ∠GML
- Twice of ∠LJM
(a)
∠KGJ = 45° (Right angle)
∠MKJ = 60° (Equilateral triangle)
∠GKM
= 90° - ∠MKJ
= 90° - 60°
= 30°
∠GML
= 30° + 45° (Exterior angle of a triangle)
= 75°
Two-fifths of ∠GML
=
25 x 75°
= 30°
(b)
∠LMJ
= 180° - ∠GML
= 180° - 75°
= 105° (Angles on a straight line)
∠LJM
= 180° - 60° - 105°
= 15° (Angles sum of triangle)
Twice of ∠LJM
= 2 x 15°
= 30°
Answer(s): (a) 30°; (b) 30°
