Question

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

Explanation:

Step1: Recall triangle classification by sides

A triangle can be equilateral (all three sides equal), isosceles (at least two sides equal), or scalene (all sides different). In a triangle, equal angles are opposite equal sides. The given triangle has all three angles marked as equal (indicated by the red arcs), so all three sides must be equal.

Step2: Match with the options

• "isosceles but not equilateral" is incorrect because an equilateral triangle is a special case of isosceles (with all three sides equal), and here all sides are equal.
• "equilateral" is correct because all three sides are equal (since all three angles are equal, by the isosceles triangle theorem converse, all sides are equal).
• "scalene" is incorrect because scalene triangles have all sides of different lengths, which is not the case here.

Answer:

B. equilateral (assuming the options are labeled as A: isosceles but not equilateral, B: equilateral, C: scalene. If the original options had different labels, adjust accordingly, but based on the text, the correct option is the one with "equilateral".)