Read four lines that are parallel with e f.
Why are the lines e f and g h said to be parallel to each other?
When are lines said to be parallel to each other?
Read four lines that are parallel to 5 6.
Four that are parallel to o p.
Is any line parallel to u v?
Can a single line be properly called perpendicular? Parallel?
If two lines are perpendicular to each other, what angle do they form?
If parallel, what angle? If oblique?
