12^{3}-9x^{2}-4x+3 in factored form by grouping

One of the same side angles of two parallel lines is 20° smaller than the other one. find the measures of these two angles.

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.

A25- foot ladder leans against a building and reaches a point of 23.5 feet above the ground .find the angle that the ladder makes with the building