Question

How can you prove a triangle is a right triangle?

Use the distance formula to see if at least two sides are congruent.
Use the slope formula to see if any sides are perpendicular.
Use the distance formula to see if all three sides are congruent.
Use the slope formula to see if any sides are parallel.

Answer 1

second choice

Explanation:

Right angle has a 45 degree angle which is perpendicular.