1. Warm up Make a chart in your notes of the perfect squares from 1 to 20. For Example: 1 2 = 1 2 2 = 4

2. Pythagorean Theorem Year 2 Sections 9.1 and 9.2

3. Old Greek Guy Pythagoras was a Greek philosopher and teacher He lived from 569 to 495 B. C. Often described as the “first pure mathematician”

4. The Theorem itself For right triangles, where a and b are the legs and c is the hypotenuse of the triangle. There are more than 200 known proofs. Check out a proof of the Theorem online at http://www.keymath.com/x19481.xml http://www.keymath.com/x19481.xml

5. Example How high up a wall will a 20’ ladder touch if the ladder is placed 5’ from the wall? 5’ Ladder 20’ Wall Step 1: Identify the hypotenuse and label it “c” hypotenuse c Step 2: Label the other two sides as “a” and “b” a Step 3: Plug in and solve. b or

6. Solve for the missing side. Ex. 1 Ex. 2 Ex. 3 5 x 4 1 2 y 6 z = 3 = 5

7. Pythagorean Triples Any three positive integers which fit the Pythagorean equation are called Pythagorean Triples. Common Pythagorean Triples are… 3, 4, 5 5, 12, 13 7, 24, 25

8. Homework Worksheet 9.1