
Mark H. answered 01/07/20
Tutoring in Math and Science at all levels
The three angles of any triangle must total 180 degrees.
By definition, an isoceles triangle must have 2 equal sides, and therefore 2 equal angles.
Two possibilities:
- A 40 degree angle at each side, and a 100-degree angle at the top.
- A 40-degree angle at the top, and a 70-degree angle at each side
Draw each one--approximately to scale--so you can visualize