What are the answers for the last two questions?

Please explain how you got your answers.

How to choose the sign of the radical in the denominator of the formula for the distance from a point to a line.

What is the similarity ratio of a cube with volume 729m^3 to a cube with volume 3375 m^3

Which statement explains how you could use coordinate geometry to prove the opposite sides of a quadrilateral are congruent? a. use the slope formula to prove the slopes of the opposite sides are the same. b. use the slope formula to prove the slopes of the opposite sides are opposite reciprocals. c. use the distance formula to prove the lengths of the opposite sides are the same. d. use the distance formula to prove the midpoints of the opposite sides are the same.