1. Do Now 5/16/11 Copy HW in your planner. Copy HW in your planner. Text p. 467, #8-30 evens, & 19 Text p. 467, #8-30 evens, & 19 Be ready to copy POTW #6. Be ready to copy POTW #6.

2. In your notebook, list as many types of triangles that you can. Then draw a picture for each one.

3. Objective SWBAT classify triangles by their angles SWBAT classify triangles by their angles SWBAT use the Pythagorean Theorem to find the lengths of the sides of a right triangle SWBAT use the Pythagorean Theorem to find the lengths of the sides of a right triangle

4. Triangles can be classified by their SIDES and ANGLES. Triangles can be classified by their SIDES and ANGLES. a° c° b° C A B b a c Triangle Review

5. Classifying Triangles by their SIDES EQUILATERAL TRIANGLE – has 3 sides of the same length. ISOSCELES TRIANGLE – has at least 2 sides of the same length. SCALENE TRIANGLE – has 3 sides of DIFFERENT lengths.

6. Classifying Triangles by their ANGLES ACUTE TRIANGLE – has 3 acute angles. RIGHT TRIANGLE – has 1 right angle. OBTUSE TRIANGLE – has 1 obtuse angle.

7. Name the TRIANGLE ACUTEorEQUIANGULAR EQUILATERAL E D F 4 4 60° 4

8. Name the TRIANGLE OBTUSE ISOSCELES 40° 100° 40° C A B 6 6 12

9. Name the TRIANGLE ACUTE SCALENE 46° 89° 45° C A B 4 5 12

10. Name the TRIANGLE RIGHT SCALENE

11. ACUTE EQUILATERAL

12. a c b hypotenuse (always across from the right angle (always across from the right angle and always the longest side ). and always the longest side ). legs right angle (90°) (90°) Section 9.3 “The Pythagorean Theorem”

13. The Pythagorean Theorem For any RIGHT TRIANGLE, the sum of the squares of the lengths of the legs, a a a a and b, equals the square of the length of the hypotenuse, c. a b c

14. Solving a Right Triangle In the triangle below, a = 6 and b = 7. Use the Pythagorean Theorem to find the length of the hypotenuse. In the triangle below, a = 6 and b = 7. Use the Pythagorean Theorem to find the length of the hypotenuse. a b c

15. Solving a Right Triangle In the triangle below, c = 10 and a = 6. Use the Pythagorean Theorem to find the length of the other leg. In the triangle below, c = 10 and a = 6. Use the Pythagorean Theorem to find the length of the other leg. a b c

16. Solving a Right Triangle In the triangle below, d and e are both 5. Use the Pythagorean Theorem to find the length of the hypotenuse. In the triangle below, d and e are both 5. Use the Pythagorean Theorem to find the length of the hypotenuse. de f The triangle is an The triangle is an ISOSCELES triangle- ISOSCELES triangle- the legs are the same length the legs are the same length

17. To Be or Not To Be… A Right Triangle Side lengths : 1, 2, 3 Side lengths : 3, 4, 5 Side lengths : 5, 12, 13

18. Your cat is at the top of a 15 foot tree. The bottom of the ladder that you will use will be placed 9 feet from the base of the tree. Can you reach the cat if the ladder is 20 feet in length? 9 feet 15 feet

19. Homework Text p. 467, #8-30 evens, & 19 Text p. 467, #8-30 evens, & 19