Chapter 1 Exploring Geometry: Points, Lines, and Angles in the Plane Section 3 Copying and Bisecting Angles Objectives: Students will be introduced to angles and be able to draw and bisect angles using a compass.

Chapter 1Section 3 - Copying and Bisecting Angles 2 An angle (  ) is a figure formed from two rays (called the sides of the angle) with the same endpoint (called the vertex of the angle). Angle Vertex Point X Side XW Side XY W Y X

Chapter 1Section 3 - Copying and Bisecting Angles 3  If there is only one angle at a vertex, you can use a single letter to name the vertex of the angle.  B A C B 1  An angle can also be named by a number.  1  ABC or  CBA Vertex  If there is more than one angle at a vertex, name the angle using three letters, with the middle letter being the vertex. Naming an Angle

Chapter 1Section 3 - Copying and Bisecting Angles 4 Example 1 1.Name the angle in as many ways as possible. 2.Name the sides and the vertex of the angle. Q S R 3 Answer:  R,  3,  QRS, or  SRQ Answer: Sides - RQ and RS Vertex - Point R