Diagram
OppositeAdjacentHypotenuse
Formula
cos(θ) = adjacent ÷ hypotenuse
The side names are relative to angle θ.
Example
If adjacent = 4 and hypotenuse = 5:
cosine = 4 ÷ 5 = 0.8
Learn how the cosine ratio compares two sides of a right-angled triangle.
cos(θ) = adjacent ÷ hypotenuse
The side names are relative to angle θ.
If adjacent = 4 and hypotenuse = 5:
cosine = 4 ÷ 5 = 0.8