Triangle Solver
by Freya Holmér

Click sides & angles to mark them as known or unknown,
and it will display what is solvable or cursed
Sum of angles
$$A+B+C=\tau / 2$$
Law of cosines
$$\begin{aligned} a^2 & ={c^2+b^2-2cb} \cos A\\ b^2 & ={a^2+c^2-2ac} \cos B\\ c^2 & ={b^2+a^2-2ba} \cos C \end{aligned}$$
Law of sines
$${a \over \sin A} = {b \over \sin B} = {c \over \sin C} $$
Right triangle formulas
Pythagorean theorem
$$ c^2 = a^2+b^2 $$
Trigonometric ratios
$$\begin{aligned} \sin A &= {a \over c} & \sin B &= {b \over c} \\ \cos A &= {b \over c} & \cos B &= {a \over c} \\ \tan A &= {a \over b} & \tan B &= {b \over a} \end{aligned}$$