Slope of a straight line

Find the slope of the line through (3, −2) and (7, 6), and its inclination angle to the nearest degree.

Show that (−1, −1), (1, 2) and (3, 5) are collinear.

Find the slope of a line perpendicular to the line through (0, 6) and (4, 0).

Prove that A(1, 1), B(5, 3), C(3, 7) is a right triangle and name the right angle.

Find k so that the line through (1, 2) and (3, k) is parallel to the line through (0, 0) and (2, 6).