1. Lesson 8 – 3 Special Right Triangles
Geometry
Lesson 8 – 3
Special Right Triangles
Objective:
Use the properties of triangles.
Use the properties of triangles.

2. 45-45-90 triangle Find the hypotenuse for the following: 12 + 12 = x2

3. Triangle Theorem
In a degree triangle, the legs l are congruent and the length of the hypotenuse h is times the length of the leg.

4. little different, be careful.
Find x 6
Same concept, but a
little different, be careful.
Use this setup.
x = 9(2)
x = 18

5. Find x.
x = 14

6. Find x. Same concept, only solving in different order.
Don’t forget to simplify the radical!

7. Find x.
5 = x

8. 14 20 7 10
72 + b2 = 142
102 + b2 = 202
b2 = 147

9. 30-60-90 Triangle Since 30 is x. 60 is 2(30). So 60 is 2x. 2x 2x
How can we find the length of a?

10. Triangle Theorem
In a triangle, the length of the hypotenuse h is 2 times the length of the shorter leg s, and the length of the longer leg is l is times the length of the shorter leg.

11. Find x and y. 2x 30
So y = 2x

12. Find x & y. 2x

13. Find x & y
2x = 10
x = 5 2x

14. Find x & y
x = 2(21) = 42 2x x

15. Find x & y x 2x
x = 4

16. Homework
Pg – 7 all, 8 – 32 EOE, 38, 48, 52 – 64 E