Notes #2 (1.4) 1.4 Angles Measure Standard 1.0 Students demonstrate understanding by identifying and giving examples of undefined terms… Objective: Measure and classify angles
Ray: is a part of a line, it has an endpoint (starting point) and extends indefinitely Named EF, or EG E Q P P R Opposite Rays by definition are two collinear rays with a common endpoint
Angle An angle is formed by two non-collinear rays (called the sides) with the same initial point (called the vertex) C Vertex: point A Ray (Side) Sides: AB, and AC B A Ray (Side) Vertex
Naming Angles There are three ways to name angles C B A 4 1. By using the vertex 2. By using the points on the angle C 4 B 3. By using the number inside the angle A
Interior and Exterior of Angles An angle divides a plane into 3 distinct parts. On, In, or Outside ON Points A, D, and E lie _____________ the angle M IN Points C and B lie _____________ of the angle A C OUTSIDE B Points F and G lie _____________ of the angle E F D G
Example 1 p. 32 Angles and Their Parts W X V Name all the angles that have W as a vertex 2 1 3 Name the side of <1 5 4 Z Y Write another name for <WYZ
Classwork #3 Pg. 36 (9-23)odd Homework #3 Pg. 36 (10-24)even
Notes #2 (1.4) continues 1.4 Angles Measure Standard 1.0 Students demonstrate understanding by identifying and giving examples of undefined terms… Objective: Measure and classify angles Identify and use congruent angles and the bisector of an angle
Protractor Since QP is aligned It has two scales running w/ 0 the other side of the angle can be measured at 65 degrees It has two scales running from 0 to 180 degrees in opposite directions Align the 0 on either side of the angle The center point of the protractor is on the vertex
Classifying Angles 90 < m C < 180
Congruent Angles ~ m<A = m<B <A = <B Congruent Angles: are angles with the same measure or degree Angle congruence looks like this… ~ m<A = m<B <A = <B D B C A
Example In the figure, . If and . Find the measurements of A C B D F
Angle Bisector: a ray that divides an angle into two congruent angles Angle Addition When a line divides an angle into two smaller angles Then the sum of the smaller angles equals the larger angle m< RSP + m<PST = m<RST R P S T
Classwork #4 Pg. 35 (1-8)no 6 Homework #4 Pg. 39 (13-20)