Angles in an isosceles triangle, step by step
An isosceles triangle has two equal sides, and that forces its two base angles to be equal.
The question
degrees
Isosceles triangle angles
base=baseandsum=180°
180−100=80
x=80°
- The two ticked sides are equal, so the two base angles are equal — and the three angles still add to 180°.
- Both base angles are 50°, so together they are 100°. The apex is what is left of 180°: 180 − 100 = 80.
- So x = 80°.
How it works.
- 01
The two ticked sides are equal, so the two base angles are equal — and the three angles still add to 180°.
- 02
Both base angles are 50°, so together they are 100°. The apex is what is left of 180°: 180 − 100 = 80.
- 03
So x = 80°.