Answer:
Only two sides must be equal to each other to prove an isosceles triangle
- The angles in the triangle DEF must all be acute angles- angles smaller than a right angle (90 degrees) to prove an acute isosceles triangle.
Explanation:
The characteristics that will prove that a given triangle DEF is an acute isosceles triangle is:
- Only two sides must be equal to each other to prove an isosceles triangle
- The angles in the triangle DEF must all be acute angles- angles smaller than a right angle (90 degrees) to prove an acute isosceles triangle.