# Vocab, Theorems and Postulates from chapter 8

## 17 terms

### Pythagorean theorem

In a right triangle, the sum of the squares of the legs is equal to the length of the hypotenuse squared. a²+b²=c²

### Pythagorean triple

a set of nonzero whole #'s a, b, and c that satisfy the equation a²+b²=c²

### Converse of the pythagorean theorem

if the square of the length of one side of a triangle is equal to the sum of the squares of the lengths of the other two sides, then the triangle is a right triangle.

### 45-45-90

A triangle where both legs are congruent and the length of the hypotenuse is √2 times the length of a leg.

### 30-60-90

A triangle where the length of the hypotenuse is twice the length of the shorter leg and the length of the longer leg is √3 times the length of the shorter leg.

### sine

opposite/hypotenuse

### identity

a type of equation that is true for all the allowed values of the variable.

### angle of elevation

the angle formed by a horizontal line and the line of sight to an object above the horizontal line

### angle of depression

the angle formed by a horizontal line and the line of sight to an object below the horizontal line

### vector

any quantity with magnitude and direction

### magnitude

corresponds to the distance from an initial point to the terminal point

### initial point

one point of a vector

### terminal point

second point of a vector

### resultant

the sum of two vectors