Bellwork 1.Find BE. 2.What is the midpoint of ? 3. On the (x, y) coordinate plane, M(3, -2) is the midpoint of. If the coordinate of D(5, -3), what is the coordinate of F?

1.4a Angle Measure Students will be able to name a ray correctly, identify the vertex and sides of an angle, classify it is as acute, right, obtuse or straight, and find the sum and difference of angles.

Ray Rays are labeled with two points Just like lines and segments. Rays have an arrow above the letters. Why?

Angles (defn) Angles are two rays with a common endpoint. Draw This. Draw This

Naming angles THREE WAYS Using the vertex (if no other angle shares the vertex). Using a number in the angle Using one point from one side-vertex-point from the other side (most descriptive)

Example 1 What is the vertex of <5? What is vertex of <8? Name the sides of <1. Name the sides of <2. Name <3 another way. Name <6 another way.

Classify (with partner) Match the correct word to its definition: 1.RightA. measure greater than 90 degrees 2.StraightB. Measure equal to 90 degrees 3.AcuteC. Measure equal to 180 degrees 4.ObtuseD. Measure less than 90 degrees

Example 2 Classify each angle as right, obtuse, acute or straight. a. b. c. d. e. f. g.

Example 3

Example 4

Example 5 If and, what is the measure of ?

Angle Bisector (Defn) A ray that divides an angle into two congruent ( ) angles is an angle bisector. Draw this. Draw this

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Homework Worksheet Quiz Friday over 1.4 – 1.5