Question

If 8=10 and 1=7, which describes all the lines that must be parallel?

Answer 1

I'm not sure. But i think the answer is C
You can see that none of the lines are about to/ are intersecting

Answer 2

Answer: Lines r and s and lines t and u must be parallel.

Explanation:

If
`\angle{8}\cong\angle{10}` which are alternate interior angle corresponding to line t and u.

then by Alternate interior angle property :

Lines t and u must be parallel.

If
`\angle{1}\cong\angle{7}` which are alternate exterior angle corresponding to line r and us.

then by Alternate exterior angle property :

Lines r and s must be parallel.

Hence, Lines r and s and lines t and u must be parallel.