Answer:
D
Step-by-step explanation:
Congruent sides mean that they have "EQUAL" lengths.
So, to prove to sides are congruent means that their lengths are equal.
Slope gives the slope of a line. So this can't be it.
Area gives the area of figure. Nothing to do with congruency of 2 lines.
Midpoint formula gives the coordinates of the midpoint. Nothing here.
Distance formula gives the length of sides. So, this is the one we can use to prove that a figure has congruent sides. We can place the figure in coordinate system and find the length of 2 respective sides using "distance formula"
Correct answer is D
