Warmup – grab a book

• Room 195236, • submit answers for

x and y

3.3 Parallel Lines and The Triangle Angle Sum Theorem10/24 with Quiz on 10/25

Learning Targets

• I can find missing angles of a triangle using the Triangle Angle Sum Theorem

• I can classify triangles by their sides and angles• I can use exterior angles of triangles to find missing

interior angles

Classifying Triangles by angles

•Equiangular: all angles congruent•Acute: all angles acute•Right: one right angle•Obtuse: one obtuse angle

Classifying Triangles by Sides

•Equilateral: all sides congruent• Isosceles: two sides congruent•Scalene: no sides congruent

•Triangle Angle-Sum Theorem

The sum of the measures of a triangle is 180

•On page 134, in your groups, do #1-3

• On p. 135, try #6-8

• Triangle Exterior Angle Theorem:

The measure of each exterior angle of a triangle equals the sum of the measure of its two remote interior angles

Practice

• In your book,p136• #26-28

• P.136 #31-34

• Homework

3-3 in your packet