Generally, the ratio of the vertical height h to the horizontal width l of a slope is called the slope ratio, that is, the tangent value of the slope angle (tan∠a value ∠a is the included angle between the slope and the horizontal plane). That is tan∠α. Usually expressed by "I"

Tangent of angle a = vertical distance/horizontal distance. That is: tan ∠ α = h/L.

Second, the example:

ABC slope = BE/AE

BCD slope = CF/FD

Third, the significance:

The greater the slope, the higher the slope, that is, the steeper it is.