Help please I don’t understand it

Which math sentence can be used to determine if the triangle is a right triangle?

Me, prove a quadrilateral with vertices g(1,-1), h(5,1), i(4,3) and j(0,1) is a rectangle using the parallelogram method and a rectangle method.

Which point-slope form equation represents a line that passes through (3,-2) with a slope of -4/5