Coplanar lines that don't intersect. Non-coplanar lines that don't intersect. Planes that don't intersect. A line that intersects two or more coplanar lines at different points.

Angles that occupy corresponding positions Angles that lie in between two lines and on opposite sides of the transversal. Angles that lie outside two lines and on opposite sides of the transversal. (Same Side Interior Angles) Two angles that lie in between two lines and on the same side of the transversal.

EJ, BG, CH and DI EJ BC, CD, DE, GH, HI and IJ DE AB, AE, FG, and FJ AE ABC

JL KJ JN Plane JKL

exactly one exactly one

AB ∥ CD AB Τ AC is not Perpendicular AB C You can't use the Perpendicular Postulate to prove they're perpendicular, however, you can use deductive reasoning to show they are. If AB and CD are parallel and AB and AC are perpendicular, then AC must be perpendicular to CD.

Corresponding Alternate Interior ∠1 and ∠2 are not alternate exterior angles because they're a linear pair. Alternate Exterior Same Side Interior Consecutive Interior

∠3 ∠4 ∠6 ∠6 ∠3 ∠7 ∠7 ∠8 ∠4 ∠1 ∠8 ∠3 ∠6 ∠7 Consecutive/Same Side ∠4 ∠1 ∠8 ∠3 ∠6 ∠7 Consecutive/Same Side Interior angles Alternate Exterior Angles