Question

Determine which lines, if any must be parallel. Check all that apply.

Answer 1

a║b

Lines are Parallel by the Lines Perpendicular to a Transversal Theorem.

1) Examining that graph, we can see that:

Note that the Perpendicular Transversal Theorem states that

So since they are perpendicular we can write out other right angles, the converse of that theorem states that "if there are two lines perpendicular to the same line" then they are parallel.

a║b

And the reasoning is:

Lines are Parallel by the Lines Perpendicular to a Transversal Theorem.