Plz help me because I need it

The construction of copying qpr is started below. the next step is to set the width of the compass to the length of ab. how does this step ensure that a new angle will be congruent to the original angle?

Simplify 1/3 12x - 6 a. -2x-1 b.-2x-8 c.-x+4 d.3x+10 e. 4x-2

Need asap i will give brainliest and 98 points classify each pair of numbered angles corresponding, alternate interior, alternate exterior or none o these