1 1 Assignment Answers Any questions Answers in

1 -1 Assignment Answers. Any questions? • • *Answers in red have other possible answers.

Section 1 -3 Part A: Measuring Angles Rigor: Measuring, naming, and classifying angles Relevance: Angles describe rotation

What are angles? • An angle is a figure formed by two rays, called sides, with a common endpoint called the vertex (plural: vertices). • There are 3 ways to name an angle: • By the vertex R • By a number in the interior 1 • With 3 points: one from each side and the vertex in the middle SRT or TRS • If more than 1 angle shares a vertex you can NOT name the angle solely by its vertex!

Example 1: Naming Angles A) What are 2 other names for B) Why can’t 1 be named

Measuring Angles • Angles describe rotation, NOT length • Angles are measured in degrees using a protractor or in radians. (we will focus on degrees for now) Read “the measure of angle AOB is 125 degrees”

Classifying Angles By Their Measure • Angles with the same measure are congruent angles. Symbol for congruent angles in pictures

Example 2: Measuring and Classifying Angles • What are the measures of LKN, JKL, and JKN? • Classify each angle as acute, obtuse, right, or straight.

Example 3: m DEG = 115°, and m DEF = 48°. Find m FEG

Example 4 M O 3 x - 2 x N P

Angle Bisectors • An angle bisector is a ray that divides an angle into two congruent angles. JK bisects LJM; thus LJK KJM.

Example 5: Last example! KM bisects JKL, m JKM = (4 x + 6)°, and m MKL = (7 x – 12)°. Find m JKM.

Assignment 1 -3 Part A • Heading: Section 1 -3 part A Textbook pg 24 - 26 • Problem #s: 3, 8, 12, 17, 18, 24, 27, 30, 34, 41, 45 • Draw a diagram if one is not provided for you. Show all work! • Due Thursday for periods 1 & 5 • Due Friday for periods 2, 4, 6, & 7