How can we help?

You can also find more resources in our Help Center.

parallel lines

lines that are coplanar, but never intersect

skew lines

lines that aren't coplanar, but never intersect

transversal

a line that intersects 2 more parallel lines

corresponding angles

occupy the same position on each parallel line

alternate interior angles

inside (between) the parallel lines one on each parallel line ( one on each parallel lines) and on opposite lines of the transversal

alternate exterior angles

outside the parallel lines one on each and on opposite sides of the transversal

consecutive interior angles

between the 2 parallel lines on the same side of the transversal

flow proof

uses arrows to show the flow of the logical argument