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This lesson covers the concepts of finding midpoints and calculating distances between points in coordinate geometry. It explains how to apply the midpoint formula to find the coordinates of a midpoint given two endpoints. Additionally, it demonstrates the use of the distance formula to find the distance between two points with practical examples. You will learn to derive coordinates of unknown endpoints using midpoint information and verify if two segments are congruent by comparing distances.
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Objectives Develop and apply the formula for midpoint. Use the Distance Formula to find the distance between two points.
Example 1: Finding the Coordinates of a Midpoint Find the coordinates of the midpoint of PQ with endpoints P(–8, 3) and Q(–2, 7). = (–5, 5)
Example 2: Finding the Coordinates of an Endpoint M is the midpoint of XY. X has coordinates (2, 7) and M has coordinates (6, 1). Find the coordinates of Y. Step 1 Let the coordinates of Y equal (x, y). X M Y (2,7) (6,1) (x,y)
– 2 – 7 –2 –7 Example 2 Continued Step 2 Set the coordinates equal. Multiply both sides by 2. 12 = 2 + x Simplify. 2 = 7 + y Subtract. –5 = y 10 = x Simplify. The coordinates of Y are (10, –5).
Find FG and JK. Then determine whether FG JK. Example 3: Using the Distance Formula Step 1 Find the coordinates of each point. F(1, 2), G(5, 5), J(–4, 0), K(–1, –3)
Example 3 Continued Step 2 Use the Distance Formula.