So I kind of get proofing but I am lost for what you call it when two sides that aren't adjacent are supplementary. Is it just supplementary angles? I want to say either <3 and <1 are congruent or <2 and <3 are congruent. If I could get help on the rest of the problem that would be much appreciated.

Let angle 4 denote the angle adjacent to angle 3 on the right side (so between lines a and b, to the right of line c). Angles 3 and 4 are then supplementary.

Lines a and b are parallel, so angles 1 and 4 are congruent because they are alternating interior angles.

By the transitive property, angles 2 and 4 are also congruent.

Again, transitively, angles 2 and 3 are supplementary.

Let angle 5 denote the angle to the left of angle 2 (between a and b, to the left of d). Angles 5 and 2 are supplementary.

Transitively, angles 5 and 3 are congruent.

These two angles correspond to one another, so lines c and d are parallel.

4

step-by-step explanation:

points are handed out whenever you post answers.

brainliest answers are handed out by the person asking the question, so whether your answer is picked depends entirely on whether the asker bothers to pick

if you're asking about your rank, it depends on having a certain number of points and a certain number of brainliest answers. for example, at the time of this writing, i have 44338 points out of 15000 needed for the next (nearly triple the requirement! ) but i only have 24 out of 50 required brainliest answers. this number decays, meaning after a certain amount of time (i think about a month), the total number of brainliest answers you've earned doesn't count toward this total. (i've been stuck at the same rank for a long

the lesson to learn here is that you shouldn't worry about points or rank. chances are, no matter how good an answer you may provide, your efforts will go mostly unnoticed unless you focus on the newest/most active questions that get posted.