The image shows a fill-in-the-blank question about triangles. Based on the visible content and the diagram of a right triangle (with a 90° angle), the question likely refers to right triangles and the different types of angles they contain.

The likely answer is as follows:

• Right angles: Refers to the 90° angle.
• Acute angles: The remaining two angles in the right triangle, which are less than 90°.

Here's a possible full answer:

• Right angles whose measure is 90°.
• A triangle with 1 right angle and 2 acute angles.

Would you like to ask more details or clarifications?

Here are 5 related questions:

1. What is the sum of the interior angles of any triangle?
2. How do you calculate the third angle of a right triangle if one acute angle is known?
3. Can a triangle have more than one right angle? Why or why not?
4. How are the sides of a right triangle related to its angles (Pythagorean Theorem)?
5. What are the properties of the two acute angles in a right triangle?

Tip: In any triangle, the sum of all three angles always adds up to 180°.