I know:
$$\sin(x) = \frac{\text{opposite}}{\text{hypotenuse}}$$
$$\cos(x) = \frac{\text{adjacent}}{\text{hypotenuse}}$$
$$\tan(x) = \frac{\text{opposite}}{\text{adjacent}}$$
but how do you calculate $\sin(x)$, $\cos(x)$, and $\tan(x)$ without knowing any of the side's lengths?
I have looked at this question but none of the answers helped much, as I am trying to calculate accurately (i.e. $\sin(0.243)$ or $\cos(0.669)$).