Question

The vertex angle of an isosceles triangle measures 40°. What is the measure of a base angle?

40°
70°
100°
140°

Answer 1

base angle = (180° - 40°)/2 =
70°
Answer: 70°
I hope this helps.!! :))

Answer 2

The base angle is 70 degrees

How to determine the base angle?

For an isosceles triangle, we have:

Vertex angle + 2 * Base angle = 180

This gives

40 + 2 * Base angle = 180

Subtract 40 from both sides

2 * Base angle = 140

Divide both sides by 2

Base angle = 70

Hence, the base angle is 70 degrees

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