Classifying Triangles and the Sum of the Measures in a Triangle

Day 4

Day 4Math Review

Goals/Objectives Classify triangles by their angle measures and side lengths.

Use triangle classification to find angle measures and side lengths.

Find the measures of interior and exterior angles of triangles.

Apply theorems about the interior and exterior angles of triangles.

Vocabulary

acute triangleequiangular triangle

right triangleobtuse triangleequilateral triangle

isosceles triangle

scalene triangle

auxiliary linecorollaryinteriorexteriorinterior angleexterior angleremote interior angle

Activity Complete 4-1 exploration (p. 10 in packet)

You have 10 minutes. Share a few with the class

An auxiliary line is a line that is added to a figure to aid in a proof.

An auxiliary line used in the Triangle Sum Theorem

A corollary is a theorem whose proof follows directly from another theorem. Here are two corollaries to the Triangle Sum Theorem.

The interior is the set of all points inside the figure. The exterior is the set of all points outside the figure.

Exterior

Each exterior angle has two remote interior angles. A remote interior angle is an interior angle that is not adjacent to the exterior angle.

Interior Exterior

3 is an interior angle.

The remote interior angles of 4 are 1 and 2.

Work Time Complete pages 11-12 in your workbook Complete, Correct pages will be stamped Return to class bin when you are finished

Exit Quiz Complete the quiz Show any and all work that you can

Circle your answers Turn it in before you leave