In triangle , if cm, cm and , find the perimeter of the triangle to the nearest centimetre.
Firstly, we can calculate the value of . Since , we can consider the triangle below.
We can see that the length of the hypotenuse is given by Pythagoras' theorem.
Therefore, we can calculate the cosine of angle .
Now returning to the triangle , we can apply the cosine rule to calculate the length of .
Therefore, the perimeter of the triangle is given by