1. Topic 1-5
Angle Relationships

2. ANGLES
An angle is a set of points consisting of two rays, with a common endpoint
called THE VERTEX of the angle. The rays are callled SIDES or LEGS of
the angle
An angle can be classified according its measurement:
Acute angle: Measure between 0 to 90 degrees
Right angle: Measure 90 degrees
Obtuse angle: Measure between 90 to180 degrees
Straight angle: Measure 180 degrees
Reflex angle: Measure between180 to 360 degrees

3. ANGLES
In addition, an angle can be classified according its characteristics and
relationship:
Adjacent angles: They have the same vertex and a common
side, but they don’t share any interior point.
Linear pair angles: Two adjacent angles which sum 180 degrees

4. ANGLES
Vertical angles: Are the opposite pair of angles formed when two lines intersect. They are always congruent
Complementary angles: Angles adjacents or not, which sum degrees

5. ANGLES
Supplementary angles: Are angles which sum is 180 degrees

6. Congruents angles ANGLES
Angles between parallel lines crossed by a transversal
-) Co-interior angles: 2-5, 3-8
-) Co-exterior angles: 1-6, 4-7
-) Vertical angles: 1-3, 2-4, 5-7, 6-8
-) Corresponding angles: 1-5, 2-6, 4-8, 3-7
-) Alternate interior angles: 2-8, 3-5
-) Alternate exterior angles: 1-7, 4-6
Congruents
angles