Slope Angle in Soil Mechanics is defined as the angle measured between a horizontal plane at a given point on the land surface. And is denoted by θslope. Slope Angle in Soil Mechanics is usually measured using the Degree for Angle. Note that the value of Slope Angle in Soil Mechanics is always negative. Typically, the value of Slope Angle in Soil Mechanics lies in the range from -45 to 180.