Chapter 1 Basics of Geometry Essential Question What

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

1. 4 Angles and their measures Ray – A line with one endpoint Angles – A shape formed by 2 different rays that share the same initial point The rays are called the sides The initial point is called the vertex

1. 4 Angles and their measures Congruent angles – angles with the same measure Naming an angle. Three letters or a number. B 1 A Sometimes an angle is referred to by it’s vertex point. Ex. Angle 1 C Since B is the vertex of the angle the correct way to name this angle is ABC. Notice point B is between A and C.

1. 4 Angles and their measures Points in relation to the angle. Interior of the angle Exterior of the angle

1. 4 Angles and their measures Angle addition – b If ray AC is between ray AB and AD then, c Angle BAC + Angle CAD = Angle BAD a Angle BAC = 30 d Angle CAD = 45 Angle BAD = ? ?

1. 4 Angles and their measures n Bisector – a ray, line or segment that cuts an angle, line or line segment in half.

1. 4 Angles and their measures Four types of angles. Acute – measures less than 90 degrees Right – measures exactly 90 degrees

1. 4 Angles and their measures Obtuse – measures greater than 90 and less than 180 degrees Straight – measures exactly 180 degrees looks like a line and opposite rays