1. 12.4 The Distance Formula Objectives: Use the distance formula to find the distance between 2 points in a coordinate plane. Determine whether a triangle is a right triangle. Apply the midpoint formula. Standard Addressed: 2.1.11.A Use operations.

3. Ex. 1

4. Ex. 1 C. (4, 5) and (-5, 7) 9.22

6. Ex. 2

7. Ex. 2b. Given vertices P(-1, -2), Q (5, 2), and R (-3, 1), determine whether triangle PQR is a right triangle. Right Triangle

9. Ex. 3 3 + 11, 8 + 2 2 2 (7, 5)

10. Ex. 4a. The center M (3, 4). If one endpoint of a diameter is A (-4, 6), what is the other endpoint, B (x 2, y 2 )? 3 = x + (-4) 2 6 = -4 + x X = 10 4 = y + 6 2 8 = y + 6 y = 2 (10, 2)

11. Ex. 4b. If the center of a circle is M(-1, -2) and one endpoint of a diameter is A(4, 3), what is the other endpoint, B (x 2, y 2 )? -1 = x + 4 2 -2 = 4 + x X = -6 -2 = y + 3 2 -4 = 3 + y y = -7 (-6, -7)