### Notes 9B Special Right Triangles_45 -45

```Bell Work
A 15 foot ladder is leaning against a building at the 2nd floor window which is 12 feet above the ground. To the nearest foot, how far away is the bottom of the ladder from the base of the building?
Notes: 9B ­ Special Right Triangles
45-45-90
Vocabulary: Right triangles whose angles measure are ______________ 30-60-90
Special Right Triangles
or ______________are called _________________________.
Theorem 9.8
o
The hypotenuse is
45
2x
x
45
x
o
45 -45 -90 o Triangle Theorem
2 times as long as each leg
Hypotenuse = 2 leg
45 45 90
1
1
2
Example: Find the value of x.
3
45
45 45 90
2
1 1
3
o
x
Find the value of the variables.
x
1.
45
4
2.
45
9
k
h
Practice: Find the value of the variables.
2.
1.
x
7
x
3.
y
y
x
45
13
18
45
How to Write in Simplified Radical Form
Example:
45
1. 48 2. 72 3. 125
12
1.
x
2.
5
7
14
x
Pythagorean Theorem Review
c
a
2
a2 +b =c 2
b
Find the length of the missing side of the right triangle. Write your answers in
simplifest square root form.
2.
12
1.
x
5
7
14
x
Assignment:
Worksheet 9B
```