In the figure, not drawn to scale. RSTU is a square. TUV is an equilateral triangle and RT is a straight line. Find
- Two-fifths of ∠RWV
- Nine times of ∠VTW
(a)
∠URT = 45° (Right angle)
∠WUT = 60° (Equilateral triangle)
∠RUW
= 90° - ∠WUT
= 90° - 60°
= 30°
∠RWV
= 30° + 45° (Exterior angle of a triangle)
= 75°
Two-fifths of ∠RWV
=
25 x 75°
= 30°
(b)
∠VWT
= 180° - ∠RWV
= 180° - 75°
= 105° (Angles on a straight line)
∠VTW
= 180° - 60° - 105°
= 15° (Angles sum of triangle)
Nine times of ∠VTW
= 9 x 15°
= 135°
Answer(s): (a) 30°; (b) 135°
