8.5 - The Midpoint Formula

 Introduction:

This is a set of guiding questions and materials for creating your own lesson plan on introducing the midpoint formula.

 Common Core State Standards:

• G-GPE.6
• G-GPE.7

 Guiding Questions:

• What is half of 11?
  • Use a number line to locate half of 11.
  • Introduce the term midpoint.
  • Make a connection to a segment of length 11 units.
• What happens to the midpoint if we move this segment one unit to the right?
• Suppose we had started at this location, how could we have found the midpoint?
• What are the coordinates of the point between points (3, 1) and (8, 1)?
• What are the coordinates of the point between points (-3, 1) and (8, 1)?
• What are the coordinates of the point between points (2, 3) and (2, 7)?
• What are the coordinates of the point between points (2, -3) and (2, 7)?
• What are the coordinates of the point between points (2, 3) and (8, 1)?
• What are the coordinates of the point between points (x₁, y₁) and (x₂, y₂)?
• Midpoint = $\left(\frac{x_1+x_2}{2},\:\frac{y_1+y_2}{2}\right)$

8.5.1 - The Midpoint Formula

• We derive the Midpoint Formula.

• Successful Mathematics: North Carolina Common Core Math 1 Item Bank, Nagy-Lup, p. 91, problems 1-17.
• Khan Academy
• Midpoint Formula Exercises Links to an external site.

• Khan Academy
• The Midpoint Formula Links to an external site.