Selected exercises from Art of Problem Solving Pre-Algebra Chapter 10.3

Going into detail on a tricky math problem from Art of Problem Solving's Pre-Algebra book

Concept - Transversals Transversals - line that cuts across parallel lines and creates angles with the same measure. One way to see why is to imagine sliding line $\overleftrightarrow{D F}$ on top of $\overleftrightarrow{C G}$ so that point $B$ is on top of point $A$. Then, $\angle ABF$