More Applications of the Pythagorean Theorem

5 min

Narrative

The purpose of this Warm-up is to get students thinking about the relationship between the values of aa, bb, and cc in the Pythagorean Theorem by looking at Pythagorean triples.

Launch

Arrange students in groups of 2. Give partners 2 minutes of quiet work time, and follow with a whole-class discussion.

Student Task

A Pythagorean triple is a set of three integers aa, bb, and cc where a2+b2=c2a^2+b^2=c^2. An example of a Pythagorean triple is 3, 4, and 5 because 32+42=523^2+4^2=5^2. Find other Pythagorean triples.

Sample Response

Common Pythagorean triples: 6, 8, 10; 5, 12, 13; 8, 15,17; 7, 24, 25; 20, 21, 29; 9, 40, 41
 
Activity Synthesis (Teacher Notes)

The purpose of this discussion is to help students see patterns and similarity in right triangles. For example, one common Pythagorean triple is 3, 4, and 5, and by multiplying each value by a common factor, more triples like 6, 8, and 10 or 15, 20, and 25 can be made.

Ask students to share any Pythagorean triples they found and record and display these for all to see. Choose a few triples for the class to verify. Ask students if they notice any patterns between the triples. If not mentioned by students, draw their attention to any triples that are multiples of each other.

Standards
Addressing
  • 8.G.B·Understand and apply the Pythagorean Theorem.
  • 8.G.B·Understand and apply the Pythagorean Theorem.

20 min