I need help finding the missing angle measurement

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

The points (1, 7) and (0, 2) fall on a particular line. what is its equation in slope-intercept form?

Quadrilateral efgh was dilated with the origin as the center of dilation to create quadrilateral e'f'g'h'. the quadrilateral was dilated using a scale factor of 2.5. the lengths of the sides of quadrilateral efgh are given. what is the length of side f'g'?