The document defines and provides examples of different types of angles: - Acute, right, obtuse, straight, and reflex angles are defined by their measure in degrees. - Adjacent angles share a vertex and side. Complementary angles add to 90 degrees. Supplementary angles add to 180 degrees. - Vertical angles are formed by the same lines at a common vertex. Interior and exterior angles are formed when lines are crossed by a transversal. Alternate interior, exterior, and corresponding angles are pairs of angles in specific positions around a transversal.

1. Types of angles

2. Acute angle
• An angle whose measure is less than 90
degrees. The following is an acute angle

3. Right angle
• An angle whose measure is 90 degrees. The
following is a right angle

4. Obtuse angle
• An angle whose measure is bigger than 90
degrees but less than 180 degrees. Thus, it is
between 90 degrees and 180 degrees.

5. Straight angle
• An angle whose measure is 180 degrees. Thus,
a straight angle look like a straight line. The
following is a straight angle.

6. Reflex angle
• An angle whose measure is bigger than 180
degrees but less than 360 degrees. The
following is a reflex angle.

7. Adjacent angles
• Angle with a common vertex and one
common side. <1 and <2, are adjacent angles.

8. Complementary angles
• Two angles whose measures add to 90
degrees. Angle 1 and angle 2 are
complementary angles because together they
form a right angle.
Note that angle 1 and angle 2 do not have to
be adjacent to be complementary as long as
they add up to 90 degrees

9. Complementary angles

10. Supplementary angles
• Two angles whose measures add to 180
degrees. The following are supplementary
angles.

11. Vertical angles
• Angles that have a common vertex and whose
sides are formed by the same lines. The
following(angle 1 and angle 2) are vertical
angles.

12. Angles 3,4,5,8 are interior angles
Angles 1,2,6,7 are exterior angles
• When two parallel lines are crossed by a third
line(Transversal), 8 angles are formed. Take a
look at the following figure

13. Alternate interior angles
• Pairs of interior angles on opposite sides of
the transversal.
For instance, angle 3 and angle 5 are alternate
interior angles. Angle 4 and angle 8 are also
alternate interior angles

14. Alternate exterior angles
• Pairs of exterior angles on opposite sides of
the transversal.
Angle 2 and angle 7 are alternate exterior
angles.

15. Corresponding angles
• Pairs of angles that are in similar positions.
Angle 3 and angle 2 are corresponding angles.
Angle 5 and angle 7 are corresponding angles