1. Angle presentation

2. Obtuse angle
An obtuse angle is an angle more than 90 degrees and less than 180 degrees.

3. Acute angle
A acute angle is an angle less than 90 degrees but more than 0 degrees.

4. Right angle
A right angle is an angle whose measure is exactly 90 degrees.

5. Straight angle
A straight angle is an angle that measures exactly 180 degrees.

6. Vertical angle
Vertical angles are angles that oppisite each other when two lines cross.

7. Adjacent angle
Adjacent angles are when two angles have a common vertex and don’t overlap.

8. Complementary angle
A complementary angle is when two angles add up to 90 degrees.

9. Supplementary angle
A supplementary angle is when two angles add up to 180 degrees.