Question 176410
Either your dimensions are in error or your slope ratio is in error.  The slope on the 30' side of the 3' tall hill is 10:1, or if the slope is actually 3:1 and the length of the base on that side is actully 30', then the hill is 10' tall.


The other thing that you don't really describe well is the shape of the base of the hill.  30' by 40' could be the sides of a rectangle, or they could be the lengths of the minor and major axes of an ellipse.  For the purposes of your application the precision needed is probably low enough that it doesn't matter much, but nevertheless you should be more descriptive here.


Write back with some more detail and someone can try to help you.