Angle is the union of two noncollinear rays that have a common endpoint. The endpoint of an angle is called vertex, while the two rays are called the sides of the angle or arm. An Angle separate the points into three areas. An Angle separate the points into three areas. • Interior • Exterior • Angle itself Interior of an angle. This is set of points which are bounded within the two sides of the angle. Interior of an angle. This is set of points which are bounded within the two sides of the angle. Interior points are Point D, A and F Exterior of an angles. This is a set points that are not bounded within the two sides of the angle. Exterior of an angles. This is a set points that are not bounded within the two sides of the angle. Exterior points are Points B and C Angle Itself – this is a set points that lie on the sides of the angle including the vertex. Angle Itself – this is a set points that lie on the sides of the angle including the vertex. Points G, Q, E, R How are angles named? Three points. We will use a distinct point on each side of the angle and vertex. Note: the vertex must be written in middle. Three points. We will use a distinct point on each side of the angle and vertex. Note: the vertex must be written in middle. ∠π΄π΅πΆ ππ ∠πΆπ΅π΄ Vertex. We can name angle using its vertex. Vertex. We can name angle using its vertex. ∠π΅ Symbol or notation. In naming angles, we can also use specified symbols or numbers. Symbol or notation. In naming angles, we can also use specified symbols or numbers. ∠1