A road cutting across parallel tracks is a transversal. Look for labeled angles between the tracks on opposite sides of the road. They form alternate interior angles: angles between parallel lines on opposite sides of a transversal are equal. Check their positions before subtracting from ; that subtraction finds a neighboring angle, not its match.
Hints
- Hint 1
Look between the tracks. Angles in that space are interior angles. The two labeled angles sit on opposite sides of the road. What kind of pair does that make them?
- Hint 2
The road is a transversal, a line crossing both tracks. Across parallel tracks, alternate interior angles have equal measures. How does that connect to the marked angle?
Step-by-step
Match alternate interior angles
Step 1Identify the equal-angle pair
No Desmos needed. A parallel-line angle fact gives the measure directly. Both labeled angles lie between the tracks: one is below Track 1, and the other is above Track 2. They’re on opposite sides of the road, so they’re alternate interior angles. Because the tracks are parallel, their measures are equal:
- Step 2
Use the marked measure
The angle below Track 1 is marked , so put that given measure into the equality:
The angle at Track 2 measures . Choice A.