1. Lesson 8-4 Special Right Triangles (page 300) Essential Question How can you apply right triangle facts to solve real life problems?

2. Special Right Triangles The theorems presented here will provide short cuts to finding sides of special right triangles, BUT DO NOT FORGET the Pythagorean Theorem!

3. In a 45º - 45º - 90º triangle, the hypotenuse is times as long as a leg. Theorem 8-6 a ____ a Note: A 45º - 45º - 90º ∆ is an isosceles right ∆ with congruent legs. 45º

4. hypotenuse = leg x = _______ a a 45º

5. Example 1 (a): Find the length of the hypotenuse in the 45º-45º-90º∆. legs = 5 … hypotenuse = ______ hypotenuse = leg

6. Example 1 (b): Find the length of the hypotenuse in the 45º-45º-90º∆. legs = … hypotenuse = ____ hypotenuse = leg

7. Example 1 (c): Find the length of the hypotenuse in the 45º-45º-90º∆. legs = … hypotenuse = _____ hypotenuse

8. Example 1 (d): Find the length of the legs in the 45º-45º-90º∆. hypotenuse = … legs = ____ hypotenuse = leg

9. Example 1 (e): Find the length of the legs in the 45º-45º-90º∆. hypotenuse = 10 … legs = _____ hypotenuse = leg

10. Example 1 (f): Find the length of the legs in the 45º-45º-90º∆. hypotenuse = … legs = _____ hypotenuse = leg

11. In a 30º - 60º - 90º triangle, the hypotenuse is twice as long as the shorter leg, & the longer leg is times as long as the shorter leg. Theorem 8-7 b A a The shorter leg is opposite the 30º angle and the longer leg is opposite the 60º angle. c B C 30º 60º

12. b A a c B C 30º 60º 30º - 60º - 90º triangle short leg long leg hypotenuse

13. hypotenuse = 2 short leg b A a c B C 30º 60º long leg = short leg shorter leg = a hypotenuse = c = 2a longer leg = b = a

14. hypotenuse = 2 short leg A a 2 a B C 30º 60º long leg = short leg It checks!

15. Example 2 (a): Find the other 2 sides of the 30º-60º-90º∆. shorter leg = 2 hypotenuse = ______ longer leg = ________ hypotenuse = 2 short leg long leg = short leg

16. Example 2 (b): Find the other 2 sides of the 30º-60º-90º∆. hypotenuse = 12 shorter leg = ______ longer leg = ________ hypotenuse = 2 short leg long leg = short leg

17. Example 2 (c): Find the other 2 sides of the 30º-60º-90º∆. longer leg = shorter leg = ______ hypotenuse = ________ hypotenuse = 2 short leg long leg = short leg

18. Class Activity Classroom Exercises on page 301 #1 to #9.

19. Assignment Written Exercises on pages 302 & 303 RECOMMENDED: 1 to 15 odd numbers, REQUIRED: 17, 19, 20 to 29 ALL numbers * 32 & 36 * Prepare for Quiz on Lessons 8-3 & 8-4 How can you apply right triangle facts to solve real life problems?