What does the remainder of a synthetic division problem mean? (What is it a part of?)

Find the solutions for a triangle with a =16, c =12, and b = 63º

Aregular pentagon with a perimeter of 21 inches is dilated by a scale factor of 5/3 to create a new pentagon. what is the perimeter of the new pentagon?

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'