How can we help?

You can also find more resources in our Help Center.

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.

tangent

opposite/adjacent

sine

opposite/hypotenuse

cosine

adjacent/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

adding vectors property

<x₁+x₂ , y₁+y₂>