Just for fun… do these (on the back of your warm up) 1.Name 2 pair of alternate interior angles  5 &  3 and  4 &  1 2.What is the sum of m  1 + m  2 + m  3? 180° 3.If m  4 = 65° and m  5 = 50°, what is m  2? 65° Find all the angle measures 50° 40° 90° 40° 90° 130° 50°

Just a little quickie… ♥Please get pg 173 off the front desk and do problems 5-20…. ♥We’re just getting a head start on today’s assignment… ♥We’ll have notes in 15 minutes… ♥Go

5.2 Triangle Sum Theorem & Exterior Angle Theorem

Objectives---What we’ll learn… Find the measurement of a missing angle by using Triangle Angle Sum Theorem. Find the measurement of a missing angle by using Exterior Angle Theorem.

Triangle Sum Theorem The sum of the angle measures in a triangle equal 180°  1 +  2 +  3 = 180°

Isosceles Triangles 2 congruent sides2 congruent base angles

Isosceles Triangles & Angle Sum Theorem  E +  W +  H = 180 o  W   H  E + 2(  W) = 180 o Base Angles are congruent.

Exterior Angle Theorem The measure of an exterior angle in a triangle is the sum of the measures of the 2 remote interior angles exterior angle remote interior angles  A =  C +  D

Exterior Angle Theorem The measure of an exterior angle in a triangle is the sum of the measures of the 2 remote interior angles exterior angle remote interior angles  4 =  1 +  2

Example 1 on Exterior Angle

Example 2 on Exterior Angle

Example 3 on Exterior Angle (more challenging)

Example 4 on Exterior Angle (more challenging)

Shortcut: Interior  1+ Interior  2+ Interior  3 = Triangle INTERIOR Angle Sum 2. Triangle EXTERIOR Angle Sum Remote Interior  1 + Remote Interior  2 = Exterior Angle

an example with numbers x 82° 30° y find x & y x = 68° y = 112° 40x10x 2 30xfind all the angle measures 80°, 60°, 40° Do you hear the sirens?????

Finish the assignment