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Geometry : Midpoints in the Coordinate Plane

Published on September 05, 2012

Overview

Beginning with horizontal or vertical segments, students will show the coordinates of the endpoints and make a conjecture about the coordinates of the midpoint.

Key Steps

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    On page 1.3, students will first see a line segment and the coordinates of the endpoints displayed.  Students should then make a prediction about the coordinates for the midpoint of the segment.

  • Image

    On page 2.2, students will first see a diagonal segment and the coordinates of the endpoints.  Students can then drag the endpoints to create a different diagonal segment and make a prediction for the new coordinates of the midpoint.

  • Image

    You can discuss how to calculate the coordinates of the midpoint of a segment if the coordinates of the endpoints are know.  Then, challenge students to write a formula or a rule for calculating midpoints.