1. The problem is to classify a triangle by its sides based on the given information. 2. The triangle has two sides marked as equal, indicated by the red arc symbols on two angles. 3. A triangle with exactly two equal sides is called an isosceles triangle. 4. An equilateral triangle has all three sides equal, which is not the case here. 5. A scalene triangle has all sides of different lengths, which is also not the case here. 6. Therefore, this triangle is an isosceles triangle but not equilateral. 7. Summary: Since two sides are equal and the third is different, the triangle is isosceles but not equilateral.