Question

An exterior angle of a triangle is 110^o; and one of the interior opposite angles is 30^o, then the other two angles of the triangle are

• A. 60^o, 70^o
• B. 50^o, 60^o
• C. 120^o, 80^o
• D. 70^o, 80^o

Answer 1

The correct option is D

70^o, 80^o

Exterior angle of a triangle is equal to the sum of interior opposite angles of the triangle.

Hence, 30^o + other interior angle = 110^o

other interior angle = 80^o

By the angle sum property of a triangle

30^o + 80^o + third angle = 180^o

Third angle = 70^o