Angle ADC measures ___.
120°
90°
60°
30°
In ΔADC, all sides are equal and hence it is an equilateral triangle. Each angle of an equilateral triangle is 60°. Hence, ∠ADC is 60°.
The angles of a triangle are in the ratio 1:2:3. The measure of the largest angle is(a) 30∘(b) 60∘(c) 90∘(d) 120∘