1. Warm-up 6 th Hour – Chapter 6 Test Scores: 100, 98, 95, 94, 92, 92, 88, 85, 83, 82, 72, 70, 67, 66, 62, 58, 7 MeanMedian ModeRange What happens to the mean if you take the 7 out of the data set?

2. Section 9-1 Apply the Distance and Midpoint Formulas

3. Vocabulary Distance Formula – The distance between (x 1, y 1 ) and (x 2, y 2 ) is d = √(x 2 – x 1 ) 2 + (y 2 – y 1 ) 2 Midpoint Formula – x 1 + x 2, y 1 + y 2 2 2 Scalene Triangle – No sides equal Isosceles Triangle – Two sides equal Equilateral Triangle – All sides equal

4. Example 1 What is the distance between (-5, 1) and (-3, 2)? d = √(x 2 – x 1 ) 2 + (y 2 – y 1 ) 2 (x 1, y 1 ) d = √(-3 – (-5)) 2 + (2 – 1) 2 (x 2, y 2 ) d = √(2) 2 + (1) 2 d = √ 5

5. Example 2 Find the midpoint of the segment joining (-2, 3) and (4, -2). x 1 + x 2, y 1 + y 2 2 2 (x 1, y 1 )(x 2, y 2 ) -2 + 4, 3 + (-2) 2 2 2, 1 2 2 1, 1 2 =

6. Example 3 Write an equation for the perpendicular bisector of the line segment joining A (5, 4) and B (-1, 6). x 1 + x 2, y 1 + y 2 2 2 (x 1, y 1 )(x 2, y 2 ) 5 +(-1), 4 + 6 2 2 4, 10 2 2 2, 5 = Step 1: Find the midpoint of the line segment.

7. Example 3 - Continued Write an equation for the perpendicular bisector of the line segment joining A (5, 4) and B (-1, 6). y 2 – y 1 x 2 – x 1 (x 1, y 1 )(x 2, y 2 ) -1 / 3 Step 2: Calculate the slope of AB. m = 6 – 4 -1 – 5 m =

8. Example 3 - Continued Write an equation for the perpendicular bisector of the line segment joining A (5, 4) and B (-1, 6). 3 Step 3: Find the slope of the perpendicular bisector. m = Step 4: Use point-slope form to find the equation. y – y 1 = m(x – x 1 ) y – 5 = 3(x – 2) y – 5 = 3x – 6 y = 3x – 1 2, 5

9. Homework Section 9-1 Pages 617 –618 4, 7, 10, 12, 18, 19, 22, 25, 32, 35, 36, 41