GCSE Maths

Cosine (cos)

Let's have a look at cos in action. Below is a right-angle triangle with a 60° angle marked and two sides. Again recall "sohcahtoa"!
RAT with 60 degree angle

By definition, cos 60°


cos 60°

= adjacent÷hypotenuse

= 1÷2

= 0·5

Cos 60° will always equal 0·5, when applied to right angle triangles.

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