Question

classify this triangle by its sides and angles.
acute and equilateral
right and isosceles, but not equilateral
acute and isosceles, but not equilateral
right and equilateral

Explanation:

1. Angle classification: All three angles are marked as equal, so each angle is $60^\circ$ (since the sum of triangle angles is $180^\circ$, $\frac{180^\circ}{3}=60^\circ$). Angles less than $90^\circ$ are acute, so this is an acute triangle.
2. Side classification: Equal angles correspond to equal sides. Three equal angles mean three equal sides, so this is an equilateral triangle.

Answer:

acute and equilateral