Question

Analyze the diagram below and answer the question that follows. If <10 and <15 are congruent, which lines are parallel? A. lines b and c B. lines c and d C. lines a and b D. No lines are parallel.

Answer 1

If angle 10 and 15 are congruent ( the same) that would mean lines a and b would need to be parallel with each other because that have the same angles.

The answer ic C.

Answer 2

Answer:

C. lines a and b

Step-by-step explanation:

Angles ∡10 and ∡11 are congruent.

Also, angles ∡15 and ∡14 are congruent.

If ∡10 and ∡15 are congruent, it means that all of four angles ∡10, ∡11, ∡14, ∡15 are congruent.

That also means that ∡9, ∡12, ∡16 and ∡16 are congruent:

∡9=180°-∡10 and ∡13=180°-∡15

Since ∡10 and ∡15 are congruent, it yields that ∡9 and ∡13 are congruent.

Same argument for ∡12 and ∡16.

Therefore, lines a and b are parallel.