## Lesson 26: The Distance and Midpoint Formulas

** Description:**The lesson begins by associating the distance between two points with the right triangle that may be formed by joining the points and extending horizontal and vertical lines through the points. This linking is generalized to derive the distance formula for any two points in the plane. The midpoint formula is then derived by taking the average of the coordinates of the two points. Using the distance formula, the equation for circle is derived and then examples follow for finding the equation of a given circle.

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**Subject(s):**- Mathematics
- Mathematics > Algebra

**Educational Level(s):**- College & Beyond

**Instructional Component Type(s):**- Curriculum: Lesson Plan

- From: San Diego Area Knowledge Exchange for Developmental Math (SAKE)
- Contributed By: SAKE Owner SAKE Owner

The lesson begins by associating the distance between two points with the right triangle that may be formed by joining the points and extending horizontal and vertical lines through the points. This linking is generalized to derive the distance formula for any two points in the plane. The midpoint formula is then derived by taking the average of the coordinates of the two points. Using the distance formula, the equation for circle is derived and then examples follow for finding the equation of a given circle.