User:AlexBrett/Rhys



Ok, ok. Here we go.

ABC is a simple (right-angled triangle). Side a is the side opposite angle A (that is, it is the line BC), side b is opposite angle B. and side c is opposite angle C.

The angle at A (labelled theta, θ) is calculated thus: $$ theta = sin^{-1} \frac {a}{c} $$