The Law of Cosines (also called the Cosine Rule) is very useful for solving triangles
The cossinus is the ratio between the adjacent catet and the hypetenuse.
It can be used to find sides and angles in triangles.
Example in a triangle ABC. AB=2cm, BC=hypotenuse=x and angle ABC (angle in point B) is 45 degrees
The equation will be as follows:
$$\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{cos}}{\left({\mathtt{45}}^\circ\right)} = {\frac{{\mathtt{2}}}{{\mathtt{x}}}}$$
