Pythagorean Theorem

Imagine these three squares were made of flattened gold, and you were offered either the one large square or the two small squares. Which would you choose?

The Pythagorean Theorem

Check out this animated proof of the Pythagorean Theorem

http://www.usna.edu/MathDept/mdm/pyth.html

Here is the Chinese proof from Chou Pei Suan Ching dated somewhere between 300 BC and 200 AD.

Format for solving Pythagorean Theorem Problems

1. Write the formula

2. Substitute what you know

3. Solve

4. Label

Try these at home. Watch the video below first, then solve the three problems below - we will go over them in class.

Video of the format for Pythagorean Theorem:

http://www.wayland.k12.ma.us/middle_school/hagan/info/activitylinks/PythagoreanTheorem.html

When we solve circumference and area of circle problems we also use the format (#1-4) above. Try these three problems tonight.

1. Draw a right triangle. Label on leg 9 cm, label the other leg 12 cm. Use the Pythagorean theorem (a²+b²=c²) to find the longest side (called the hypotenuse). This long side is always the one marked "c."

2. Use the formula for the circumference of a circle (C = 2 π r ) to find the circumference of a circle with a radius of 6 inches.

3. Use the formula for the area of a circle (A = π r² ) to find the area of a circle with a radius of 8 inches.