The angle framed by the line of sight and the even plane for an object below the horizontal is known as angle of depression. It can be estimated from the known values of opposite and the adjacent sides of the object.
Find the Angle of Depression
Code to add this calci to your website
Just copy and paste the below code to your webpage where you want to display this calculator.
θ = atan(Opposite Side / Adjacent Side)
atan = Arc Tangent