Lesson 8
Triangles with 3 Common Measures
Let’s contrast triangles.
8.1: 3 Sides; 3 Angles
Examine each set of triangles. What do you notice? What is the same about the triangles in the set? What is different?
Set 1:
Set 2:
8.2: 2 Sides and 1 Angle
Examine this set of triangles.
 What is the same about the triangles in the set? What is different?

How many different triangles are there? Explain or show your reasoning.
8.3: 2 Angles and 1 Side
Examine this set of triangles.
 What is the same about the triangles in the set? What is different?

How many different triangles are there? Explain or show your reasoning.
Summary
Both of these quadrilaterals have a right angle and side lengths 4 and 5:
If we create two triangles with three equal measures, but these measures are not next to each other in the same order, that usually means the triangles are different. Here is an example: