1. EXAMPLE 2
Solve a real-world problem
Snake Patterns
How can you tell whether the sides of the pattern are parallel in the photo of a diamond-back snake?
SOLUTION
Because the alternate interior angles are congruent, you know that the sides of the pattern are parallel.

2. GUIDED PRACTICE
for Example 2
Can you prove that lines a and b are parallel? Explain why or why not.
Yes; Alternate Exterior Angles Converse.
ANSWER

3. GUIDED PRACTICE
for Example 2
Yes; Corresponding Angles Converse.
ANSWER

4. GUIDED PRACTICE
for Example 2
m m 2 = 180°
No; Supplementary angles do not have to be congruent.
ANSWER