# If I have a right angled triangle, how do I work out an angle if I have 1 side and also the 90 degree angle?

Having the length of one side and knowing that one angle is ${90}^{\circ}$ is not sufficient information to determine the other angle(s).
Notice that the $\textcolor{g r e e n}{\text{green"), color(red)("red}} ,$ and $\textcolor{b l u e}{\text{blue}}$ triangles all have a right angle and one side with a common length, but the other angles are not fixed values.