Related Topics:
Lesson
Plans and Worksheets for Grade 8
Lesson
Plans and Worksheets for all Grades
More
Lessons for Grade 8
Common Core For Grade 8
Examples, solutions, and videos to help Grade 8 students learn how to explain a proof of the Pythagorean Theorem using similar
triangles and another proof using area.
New York State Common Core Math Grade 8, Module 7, Lesson 15
Worksheets for Grade 8
Lesson 15 Student Outcomes
• Students know that the Pythagorean Theorem can be interpreted as a statement about the areas of similar
geometric figures constructed on the sides of a right triangle.
• Students explain a proof of the Pythagorean Theorem.
Lesson 15 Summary
The Pythagorean Theorem can be proven by showing that the sum of the areas of the squares constructed off of the
legs of a right triangle is equal to the area of the square constructed off of the hypotenuse of the right triangle.
Lesson 15 Classwork
Discussion
This discussion is an opportunity for students to practice explaining a proof of the Pythagorean Theorem using similar
triangles.
• To prove the Pythagorean Theorem, a
2 + b
2 = c
2, use a right triangle, shown below. Begin by drawing a segment from the right angle, perpendicular to side AB through point C. Label the intersection of the
segments point D.
Discussion
• Now, let’s apply this knowledge to another proof of the Pythagorean Theorem. Compare the area of similar
figures drawn from each side of a right triangle.
Pythagorean Theorem proof from similar right triangles
Try out our new and fun Fraction Concoction Game.
Add and subtract fractions to make exciting fraction concoctions following a recipe.
There are four levels of difficulty: Easy, medium, hard and insane. Practice the basics
of fraction addition and subtraction or challenge yourself with the insane level.
We welcome your feedback, comments and questions about this site or page. Please submit your feedback or enquiries via our Feedback page.