# Chapter 8 Geometry

## 29 terms

a²+ b² = c²

### When is the Pythagorean Theorem used?

only in right triangles

3,4,5
5,12,13
8,15,17
7,24,25

if a² + b² ⟨ c²

a²+ b² = c²

if a² + b² ⟩ c²

### Sides of A right Triangle

2 legs and 1 hypotenuse

### Hypotenuse

is the longest side of the triangle

### Special Right traignles

45°- 90°- 45° and 30°- 60°- 90°

### 45°- 90°- 45° Triangles

is an isosceles Right triangle, which means it has 2 congruent legs and one hypotenuse

### 45°- 90°- 45° legs

the length of the legs are congruent

### 45°- 90°- 45° hypotenuse

and the length of the hypotenuse is leg√2

### 30°- 60°- 90° Triangles

a short leg, a long leg and a hypotenuse.

### 30°- 60°- 90° Hypotenuse

2 x the shorter leg

### 30°- 60°- 90° Longer leg

√3 x the shorter leg

### 30°- 60°- 90° Shorter leg

½ x the hypotenuse

### WIDUPT

When In Doubt Use the Pythagorean Theorem

### SOHCAHTOA

Sine is opposite over the hypotenuse
Cosine is adjacent side over hypotenuse
Tangent is opposite over adjacent

### Sine

opposite over hypotenuse

### ϴ (theta)

symbolizes the unknown angle

### Sinϴ=a/b

ϴ= Sin⁻¹(opp/hyp)

### when finding the measurement of an angle, what do you use?

You use the inverse of tangent, or cosine or sine.

tan⁻¹

sin⁻¹

cos⁻¹