Question

classify this triangle by its sides.
isosceles but not equilateral
equilateral
scalene

Explanation:

Step1: Recall triangle side - classification definitions

• An equilateral triangle has all three sides equal.
• An isosceles triangle has at least two sides equal.
• A scalene triangle has all three sides of different lengths.

Step2: Analyze the given triangle

From the angle markings (in a triangle, equal angles are opposite equal sides), we can infer that two sides are equal. Since all three angles are not equal (the vertex angle is different from the other two base - angles), the three sides are not all equal. So, it is an isosceles triangle (because of two equal sides) and not an equilateral triangle (since not all three sides are equal).

Answer:

isosceles but not equilateral