Changes

===Slope in degrees===

===Slope in degrees===

Expressing a slope in degrees requires using the ''inverse tangent'' trigonometric function.  

Expressing a slope in degrees requires using the ''tangent'' trigonometric function.  

e.g.:<math>\tan \theta =\left ( \frac{4\ m}{12\ m} \right ); \theta =\tan^{-1}\left ( 0.33 \right )=18.3^{\circ}</math>

e.g.:<math>\tan \theta =\left ( \frac{4\ m}{12\ m} \right ); \theta =\tan^{-1}\left ( 0.33 \right )=18.3^{\circ}</math>