Are the two triangles similar? How do you know?
So,
What do you need to show that the triangles are similar?
To use the AA
By the Triangle Angle-Sum Theorem,
Here are two other ways to determine whether two triangles are similar.
Theorem
If an angle of one triangle is congruent to an angle of a second triangle, and the sides that include the two angles are proportional, then the triangles are similar.
If …
Then …
You will prove Theorem 7-1 in Exercise 35.
Theorem
If the corresponding sides of two triangles are proportional, then the triangles are similar.
If …
Then …
You will prove Theorem 7-2 in Exercise 36.