Students will learn what Pythagorean triples are, and solve some problems involving them. Students should also be shown that all Pythagorean triples can be generated from the primitive Pythagorean triples. After that, show students the formula for generating Pythagorean triples, as seen here. Here's an interesting problem: Have students mentally find the perimeter of this trapezoid:

Next, give your students this challenge:

How Safe Are You? by NRICH

Conclude by leading this investigation:

Subtraction Magic with 3 Digits

by MathPickle