Which of the following represents a right triangle?

A triangle is defined as a right triangle if it has one angle that measures exactly 90 degrees. In this context, the crucial factor to focus on is whether any of the triangles provided by the options contain an angle of 90 degrees.

The first choice presents a triangle with angles of 30°, 60°, and 90°. This option clearly includes an angle that measures 90 degrees, which confirms it as a right triangle. The specific combination of angles demonstrates the defining characteristic of a right triangle.

The second choice involves angles of 45°, 45°, and 90°. While this option also constitutes a right triangle due to the presence of the 90-degree angle, the selection does not specify that only one answer can be correct.

The third choice offers angles of 60°, 60°, and 60°, forming an equilateral triangle, where all angles are equal and none measures 90 degrees.

The final choice lists angles of 70°, 60°, and 50°. This triangle contains no right angle as well and sums to 180 degrees, but still lacks the necessary 90-degree angle.

In summary, the presence of the 90-degree angle in the first option identifies it as a right triangle. While other options may