Chapter 1: Basics of Geometry

Chapter 1: Basics of Geometry Essential Question: What is the correct name for each undefined term?

1.5 Angle Pair Relationships • Adjacent Angles – angles that share a common side. Next to each other.

1.5 Angle Pair Relationships Vertical angles – The angles across from each other when lines intersect Angles 1 and 4 are vertical Angles 2 and 3 are vertical Vertical angles are always congruent 1 2 3 4

1.5 Angle Pair Relationships 110 a c b Where else is it 110 degrees? Angle b is vertical with 110.

1.5 Angle Pair Relationships Complimentary Angles – two angles that add to 90 degrees Which two angles are complimentary? Angle 1 = 35 Angle 2 = 45 Angle 3 = 55

1.5 Angle Pair Relationships Supplementary Angles – 2 angles that add to 180 degrees. Which angles are supplementary? Angle 1 = 45 Angle 2 = 55 Angle 3 = 135 Angle 4 = 145

1.5 Angle Pair Relationships Linear pair – Line, straight angle, or opposite rays with a ray sticking out Angles 1 and 2 form a linear pair. What else can you determine from a linear pair? All linear pairs are supplementary 1 2

1.5 Angle Pair Relationships Perpendicular lines – two lines that intersect to form a right angle.

Chapter 1: Basics of Geometry