1. Pythagorean Theorem 5-18-09 IMP3 Sia

2. Today’s Agenda Bell Ringer Hand back HW16 and quizzes Pythagorean Theorem review HW4 p. 75 due Friday, May 22 nd

3. Announcements If you missed last week’s quiz, you have until this Friday, 5- 22-09 to make them up! HW Hall this Tuesday and Thursday during 9th period ACT session Friday, May 30th in room 208 from 8am-10am # of students who completed HW16 3 rd period: 13 out of 24 (54%) 4 th period: 8 out of 17 (47%) 5 th period: 8 out of 18 (44%) Current grades: 3rd period: 3 A’s, 9 F’s 4th period: 2 A’s, 3 F’s 5th period: 3 A’s, 7 F’s

4. HW16 p. 105 1. 250,000  /300 boxes 2. 200  meters 3. No, a 30 feet board won’t be long enough because the diameter of the pond is about 31.83 feet. 4. The banner should be about 60.03 feet long.

5. What we’ve done so far… THE BASICS: lines, rays, segments, points, angles, triangles CIRCLES: radius, diameter, area, circumference, 

6. This week… RIGHT TRIANGLES: right angles, legs, hypotenuse, Pythagorean Theorem, special angles

7. Pythagorean Theorem The Pythagorean Theorem helps you find missing sides of right triangles. PT is used in: Physics Construction Plumbing Engineering Architecture

8. Right Triangles Pythagorean Theorem only applies to right triangles. You must be able to first identify parts of a right triangle to correctly use Pythagorean Theorem.

9. Pythagorean Theorem The theorem states that the squares of the lengths of the sides of the triangle are equal to the square of the hypotenuse. The legs are a and b (it doesn’t matter which leg is a or b). The hypotenuse is ALWAYS c.

10. Using the Pythagorean Theorem There is a building with a 12 ft high window. You want to use a ladder to go up to the window, and you decide to keep the ladder 5 ft away from the building to have a good slant. How long should the ladder be? 1. Draw a picture and label a, b, and c. 2. Write the Pythagorean Theorem. a 2 + b 2 = c 2 3. Plug in a, b, and c. 5 2 + 12 2 = c 2 4. Solve for the missing variable. 5. Check that you’ve solved for the missing variable, NOT THE MISSING VARIABLE SQUARED. c a b

11. Try this on your own… On a baseball diamond the bases are 90 ft apart. What is the distance from home plate to second base in a straight line? Follow the steps you just wrote down. a 2 + b 2 = c 2 90 2 + 90 2 = c 2 8100 + 8100 = 16200 = c 2 127.28 = c