NCERT Exemplar Solutions
Class 7 - Mathematics - Unit 6: Triangles - Problems and SolutionsQuestion 124
Class 7 - Mathematics - Unit 6: Triangles - Problems and Solutions
Question. 124
In ΔABC, if ∠A = ∠C, and exterior angle ABX = 140°, then find the angles of the triangle.

Answer:
∠B = 40°, ∠A = 70°, ∠C = 70°
Detailed Answer with Explanation:
Exterior ABX = 140° ⇒ ∠A + ∠C = 140°. Given ∠A = ∠C ⇒ 2∠A = 140 ⇒ ∠A = 70 ⇒ ∠C = 70 ⇒ ∠B = 40°.