Warm Up If you have a laptop, connect to: And vote for Kentlake to win $100, Encourage Family and Friends to vote for Kentlake too. Simplify each expression – (x + 20) – (3x – 10) 70 – x 190 – 3x
Correcting Assignment #3 Evens only in this section (6-22 even)
Correcting Assignment #3 Evens only in this section (6-22 even)
Correcting Assignment #3 Selected Problems in this section (22, 24-27, 29, 30)
Identify special angle pairs and use their relationships and find angle measures. Target Chapter 1-5 Exploring Angle Pairs
adjacent angles linear pair vertical angles complementary angles supplementary angles angle bisector Vocabulary
Vertical angles are two nonadjacent angles formed by two intersecting lines. 1 and 3 are vertical angles, as are 2 and 4. Vertical angles are congruent. Vertical Angles
An angle bisector is a ray that divides an angle into two congruent angles. JK bisects LJM; thus LJK KJM.
Adjacent, non-adjacent, vertical? Which is it? Example 1: Identifying Angle Pairs AEB and BED AEB and BED are adjacent AEB and CED AEB and CED are non-adjacent
What else do we know about AEB and BED? Example 1: Identifying Angle Pairs AEB and BED are adjacent angles that form a linear pair because they combine to create a straight angle. Linear pairs are also supplementary because they add to 180⁰.
What can we say about 3 and 5 which are formed by the intersection of lines l and m ? Example 2: Identifying Angle Pairs l m 3 and 5 are vertical angles, meaning they have the same measurement. And what about 1 and 2?
Example 2: Identifying Angle Pairs l m 1 and 2 are adjacent angles 1 and 2 are also congruent The ray between them is called an angle bisector If m 4 = 28⁰, what is m 2? m 2 = 14⁰
Find the measure of each of the following. Example 3: Finding the Measures of Complements and Supplements A. complement of F B. supplement of G 90 – 59 = 31 (180 – m G) 180 – (7x+10) = 180 – 7x – 10 = (170 – 7x) (90 – m F)
Example 4: Finding the Measure of an Angle KM bisects JKL mJKM = (4x + 6)° mMKL = (7x – 12)° Find mJKM. Begin by setting the angles equal to one another. mJKM = mMKL Therefore, 4x + 6 = 7x - 12
Example 4 Continued Step 1 Find x. mJKM = mMKL (4x + 6)° = (7x – 12)° +12 4x + 18 = 7x –4x 18 = 3x 6 = x Def. of bisector Substitute the given values. Add 12 to both sides. Simplify. Subtract 4x from both sides. Divide both sides by 3. Simplify.
Example 4 Continued Step 2 Find mJKM. mJKM = 4x + 6 = 4(6) + 6 = 30 Substitute 6 for x. Simplify.
Assignment #4 pg Foundation: 7 – 21 Core: 26, 28, 29, Challenge: 40