...
local unit u = GetTriggerUnit()
local real x1 = GetUnitX(u)
local real y1 = GetUnitY(u)
local real x2 = GetOrderPointX()
local real y2 = GetOrderPointY()
local real az = Определить_угол(x1,y1,x2,y2)
....

function AngleZ takes real x1,real y1,real x2,real y2 returns real
    local real z1 = GetZ(x1,y1)//высота грунта
    local real z2 = GetZ(x2,y2)
    local real a = SquareRoot(x2-x1*x2-x1 + y2-y1*y2-y1)/(z1*z1-z2*z2)
        call DisplayTextToPlayer(Player(0),0,0,R2S(a)) //проверка
        return a
endfunction