Question

In an isosceles triangle the vertex angle is equal to 40°. Find the measure of all the angles of triangle​

Answer 1

Answer:

A triangle measures 180°

In isoceles triangle two angles are equal and one is different

hence

2x+40=180

2x=180-40

2x=140

x=70°

40°, 70°, 70°

Answer 2

.

Considering an isosceles triangle \triangle△ ABC, where;

∠ A = vertex angle = 40°

∠ B = ∠ C = x

As we know that the angle sum property of the triangle says: The sum of all angles of the triangle is equal to 180°.

So, \angle∠ A + \angle∠ B + \angle∠ C = 180°

40° + x + x = 180°

2x = 180° - 40°

2x = 140°

x = $\frac{140 \degree}{2}$

x = 70°

Hence, the other angles of an isosceles triangle is 70° and 70°