1. 10.2 Slope and Perpendicular Lines p 509

2. Two nonvertical lines are perpendicular if and only if the product of their slopes is -1.

3. to prove the slope criteria for perpendicular lines.
First prove that if two lines are perpendicular, then the product of their slopes is -1.
Suppose lines m and n are perpendicular lines that intersect at point R and that neither line is vertical. Assume the slope of line m is positive. (You can write a similar proof if the slope of line m is negative.)

4. Copy the figure on a separate piece of paper
Copy the figure on a separate piece of paper. Mark your figure to show the perpendicular lines.

11. Show that each figure is the given type of quadrilateral
Show that each figure is the given type of quadrilateral. Show that DEFG is a rectangle.

12. Determine whether the quadrilateral with the given vertices is a parallelogram. If so, determine whether it is a rhombus, a rectangle, or neither. Justify your conclusions. (Hintz Recall that a parallelogram with perpendicular diagonals is a rhombus.)
1. Quadrilateral ABCD with A(-3, 0), B(1, 2), C(2,0), and D(-2, - 2)

13. 2. Quadrilateral FGHJ withF(-2,3), G(1, 2), H(2, – 1) and J(– 1, 0)