Pythagorean Theorem Lesson Plan

Instructor: Dana Dance-Schissel

Dana teaches social sciences at the college level and English and psychology at the high school level. She has master's degrees in applied, clinical and community psychology.

Want to beef up your instruction on the Pythagorean theorem? Use a video lesson to seamlessly deliver the content while allowing students the opportunity to actively apply what they've learned. For further instruction on this topic, we've included supplementary activities and related lessons.

Learning Objectives:

Upon completion of this lesson, students will be able to:

  • define the Pythagorean theorem
  • solve equations using the Pythagorean theorem


30 minutes

Curriculum Standards


Apply the Pythagorean theorem to determine unknown side lengths in right triangles in real-world and mathematical problems in two and three dimensions.

Key vocabulary

  • Pythagorean theorem
  • Hypotenuse


  • Begin by showing the video lesson The Pythagorean Theorem: Practice and Application, pausing at 00:18.
  • Ask students to try to solve the problem presented in the video lesson. Have them share their answers with the class while explaining how they arrived at the answer. You will revisit this information later in the lesson.
  • Play the video lesson again and pause this time at 2:49.
  • Have students attempt to solve the equation displayed on the screen. Have them share their answers with the class, including how they arrived at that solution.
  • Play the video lesson now and pause it at 3:31. How many of the students correctly arrived at this solution? For those who did not, have them correct their answers using the explanation offered in the video lesson.
  • Play the video lesson again and pause at 5:45. How many students were correct in their answer regarding the diagonal pathway presented at the outset of this lesson? For those who were correct, did they use the Pythagorean theorem to arrive at that answer? For those who were not correct in their calculations, have them correct their work now using the explanation provided in the video lesson.
  • Play the video lesson again and pause at 6:02. Asks students to use the Pythagorean theorem to solve the equation presented in the lesson.
  • When all students have finished solving the equation, resume the video lesson. Pause it at 6:50. How many students got it correct? For those who did not, take this opportunity to review the basics of solving equations using the Pythagorean theorem.
  • Play the rest of the video lesson now.
  • When the video lesson has played in its entirety, write ten equations on the board that require the use of the Pythagorean theorem to correctly solve. Ask students to complete the problems.
  • When all students have finished solving the equations listed on the board, ask them to swap papers with a classmate.
  • Students should now check the work of their classmate, making any needed corrections.


  • First have students use the Pythagorean theorem to solve for missing sides of a triangle. Next, have them draw the triangles using a compass and/or ruler.
  • Ask students to create a list of ten equations that require use of the Pythagorean theorem to solve. Now have the students take turns writing their equations on the board for the class to solve.

Related Lessons

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