Question

12. In an isosceles triangle ABC, if AB = AC and exterior angle C measures 140°, the measure of
three angles will be
(a) 40", 40", 100 (b) 40°, 140°, 140° (c) 70°, 70°, 70° (d) 40°, 709, 70°​

Answer 1

Answer:

40°,40°,100°

Step-by-step explanation:

exterior angle C measure 140°

interior angle C measure = 180° - 140° = 40°

AB = AC (given)

angle C = angle B

angle C = angle B=40°

sum of three angles of a triangle= 180°

A + B + C = 180°

A+40°+40°=180°

A=180° - 80°

=100°

40°,40°,100°are required angles of the triangle