Answer:
The angle of CAD is 100°.
Explanation:
Given that total angles in a triangle is 180° so you will have to find the angle of CAB :
∠CAB + ∠ACB + ∠ABC = 180°
∠CAB + 80° + 20° = 180°
∠CAB + 100° = 180°
∠CAB = 180° - 100°
∠CAB = 80°
Next, you have to subtract it from 180° because straight line have a degree of 180°
∠CAD = 180° - 80°
∠CAD = 100°