1. NOVEMBER 3, 2008 Pythagorean Theorem and Special Right Triangles

2. Similarity What makes two polygons similar?

3. Right Triangles Theorem: The altitude to the hypotenuse of a right triangle divides the triangle into two triangles that are similar to the original triangle and to each other.

4. Pythagorean Theorem Pythagorean Theorem: In a right triangle, the square of the hypotenuse is equal to the sum of the squares of the legs.

5. Pythagorean Triples Three integers (like 5,12, and 13) that satisfy the conditions of the Pythagorean Theorem are called Pythagorean Triples. If the three integers are relatively prime (meaning they have no common factors) then the three integers are know and Primitive Pythagorean Triples.

7. 45-45-90 Triangles 45°-45°-90° Theorem In a 45°-45°-90° triangle, the hypotenuse is √2 times as long as a leg.

9. 30-60-90 Triangles 30°-60°-90° Theorem In a 30°-60°-90° triangle, the hypotenuse is twice as long as the shorter leg, and the longer leg is √3 times as long as the shorter leg.

10. Try it out… Find the missing values.

11. Some more examples Find the missing values.

12. A harder example

13. Another

14. Yet another

15. Last one!