Question

what type of special triangle is this?
30°-60°-90°
equilateral
equiangular
45°-45°-90°

Explanation:

The triangle has a right angle (marked square) and two congruent legs (tick marks), meaning its non-right angles are equal ($\frac{180^\circ - 90^\circ}{2}=45^\circ$). This matches the 45°-45°-90° triangle definition.

Answer:

45°-45°-90°