This Mini-Lesson addresses the following Math Common Core State Standards.
Understand and apply the Pythagorean Theorem.
CCSS.Math.Content.8.G.B.6 Explain a proof of the Pythagorean Theorem and its converse.
CCSS.Math.Content.8.G.B.7 Apply the Pythagorean Theorem to determine unknown side lengths in right triangles in real-world and mathematical problems in two and three dimensions.
CCSS.Math.Content.8.G.B.8 Apply the Pythagorean Theorem to find the distance between two points in a coordinate system.
The entire PPT is very animated and shows why a^2 + b^2 = c^2 works. If you like it, I will provide the hands on activity that goes along with these visual powerpoint notes.