Question: Which of the following triangles is similar to triangle ABC with angles 30°, 60°, and 90°?

Options:

1. 30°, 60°, 90°
2. 45°, 45°, 90°
3. 60°, 60°, 60°
4. 30°, 30°, 120°

Correct Answer: 30°, 60°, 90°

Solution:

Triangles are similar if they have the same angles. Triangle ABC has angles 30°, 60°, and 90°, so it is similar to any triangle with the same angles.