VWXY is a square. BAX and WAY are straight lines. WV = WB and ∠AWB = 15°. Find
- ∠WVB
- ∠YXB
.
(a)
∠VWY = 45° (Right angle)
∠VWB
= ∠VWY - ∠AWB
= 45° - 15°
= 30°
∠WVB
= (180° - ∠VWB) ÷ 2
= (180° - 30°) ÷ 2
= 150° ÷ 2
= 75° (Isosceles triangle)
(b)
WV = WB = WX
BWX is an isosceles triangle.
∠WBX = ∠WXB (Isosceles triangle)
∠WXB
= (180° - ∠YWX - ∠AWB) ÷ 2
= (180° - 45° -15°) ÷ 2
= 120° ÷ 2
= 60°
∠YXB
= ∠WXY - ∠WXB
= 90° - 60°
= 30°
Answer(s): (a) 75°; (b) 30°
