Answer:
Answer is on the pic
Step-by-step explanation:
I hope it's helpful!
Answer: C) angle 2 and angle 7
Imagine the parallel lines form the boundaries of river. Angles 3, 4, 5 and 6 are considered interior angles as they are in the river. Angles 1, 2, 7, 8, 9 and 10 are exterior because they're outside the river.
Angles 2 and 7 are on opposite sides of the transversal cut that I've highlighted in red (see diagram below). So that's why they're considered alternate. Combine "exterior" and "alternate" to get "alternate exterior"
The least common multiple of 9 and 21 is 63