Triangle angle facts: summary
Compare the angle facts for any triangle, an isosceles triangle and an equilateral triangle.
Any triangle
- The interior angles add to
. - Subtract the two known angles to find the third.
Isosceles triangle
- Two sides are equal.
- The angles opposite those sides are equal.
- Subtract the vertex angle, then halve, to find each base angle.
Equilateral triangle
- All three sides are equal.
- All three angles are equal.
- Each angle is
.