The trigonometric ratios sine, cosine and tangent are used to calculate angles and sides in right angled triangles. We are now going to extend trigonometry beyond right angled triangles and use it ...

The cosine (cos) function takes the angle Ɵ and gives the answer to adjacent ÷ hypotenuse (in this example ... is the sine (sin) ratio. Practise finding angles in right-angled triangles with ...