Answer:
Equilateral triangle is the correct answer.
Step-by-step explanation:
- In the Equilateral triangle are all three sides have the same length /congruent
- All the three interior angles are also similar in an equilateral triangle
- Only the set of equilateral triangles contains members that are always similar to one another because all the angles are fixed and equal that is 60 degrees.
- Rest(trapezoids, isosceles triangles,rectangles, pentagons) does not have fixed angles in it.
