Why are corresponding angles always congruent? - why are alternate exterior angles always congruent?
why aren't alternate interior angles supplementary?

Why are Corresponding angles always congruent? --> A postulate says this is true when two parallel lines are cut by a transversal. 

Why are Alternate exterior angles always congruent? --> A theorem says this is true when two parallel lines are cut by a transversal. 

Why aren't Alternate interior angles supplementary? --> A theorem says that when two parallel lines are cut by a transversal, then same-side interior angles are supplementary and same-side exterior angles are supplementary.

step-by-step explanation:

consider an orange peel: if you want to try and lay it flat, you have to stretch it, we know exactly how things are being stretched or squashed at any given point. we have many different map projections because each has different patterns of some projections can even preserve certain features of the earth without