In the figure, ZAD and CAB are right-angled triangles. DA is parallel to CB. Find
- ∠ABC
- ∠ADC
(a)
∠CAD
= 360° - 90° - 90° - 125°
= 55° (Angles at a point)
∠ACB = ∠CAD = 55° (Alternate angles)
∠ABC
= 180° - ∠CAB - ∠ACB
= 180° - 90° - 55°
= 35° (Angles sum of triangle)
(b)
∠ADC
= 180° - ∠CAD - ∠ACD
= 180° - 55° - 80°
= 45° (Angles sum of triangle)
Answer(s): (a) 35°; (b) 45°