Lesson 15 Reasoning About Angles (Part 2)
Let’s figure out missing angle measurements.
Warm-up How Many Do You See: Obtuse Angles
How many angles do you see in the folded paper heart?
Activity 1 Shaded and Unshaded Angles
Find the measurement of each shaded angle. Show how you know.
Activity 2 Info Gap: A Whole Bunch of Angles
Your teacher will give you either a problem card or a data card. Do not show or read your card to your partner.
Pause here so your teacher can review your work. Ask your teacher for a new set of cards and repeat the activity, trading roles with your partner.
Practice Problems
Problem 1
Find the measure of each labeled angle in the drawing. Assume that:
The angles of the triangles meeting at the point in the middle of the figure are all the same.
The other angles of the triangles all have the same measure.
Problem 2
In this diagram each angle on the left hand side is the same as the corresponding angle on the right hand side. Find the measure of angles