PLEASE HELP ME :(

Tan x = 10 over 7 which is congurent to 55 degrees. how do you get the degree measument?i dont understand

$\begin{array}{rcl} \tan{( x ) } &=& \frac{10}{7} \qquad | \qquad \arctan{()}\\ \arctan{( \tan{( x ) } )} &=& \arctan{( \frac{10}{7} )} \\ x &=& \arctan{( \frac{10}{7} )} \\ x &=& 55.0079798014^{\circ} \end{array}$