Right Triangle Routine

' RightTriangle compute area and hypotenuse of a right triangle
' this routine contains examples of Cache Basic features */
 
Sub Run() 
println "Compute the area and hypotenuse of a right triangle"
println "given the lengths of its two sides."    
println
println "First, choose a unit of measurement. " 
input "(i)nches, (f)eet, (m)iles, " _
      , "(c)entimeters, m(e)ters, (k)ilometers: ", units
println
' translate units to a full word
select case left(units, 1)
    case "i" units = "inches"
    case "f" units = "feet"
    case "m" units = "miles"
    case "c" units = "centimeters"
    case "e" units = "meters"
    case "k" units = "kilometers"
    case else units = "units"
end select
 
do
    println
    input "Length of side 1: ", side1
    if (side1) = "" then exit do
loop while IsNegative( side1 )
if (side1 = "") then exit sub
 
do
    println
    input "Length of side 2: ", side2
    if (side2) = "" then exit do
loop while IsNegative( side2 )
if (side2 = "") then exit sub
 
Compute(units, side1, side2)
end sub
 
public function IsNegative(ByVal num As %String) As %Boolean
' is num negative?
    ' check in range "1" through "9"
    if (num < chr(49)) or (num > chr(57)) then
        print "  Enter a positive number." 
        return True
    else
        print "  Accepted."
        return False
    end if
end function
 
private function Compute(ByVal units As %String, _
                         ByVal A As %Integer, _
                         ByVal B As %Integer)
' compute and display area and hypotenuse
 
area  = round((( A * B ) / 2), 2)
hypot = round(sqr(( A ^ 2 ) + ( B ^ 2 )), 2)
  
println : println
println "The area of this triangle is ", area, " square ", units, "."
println
println "The hypotenuse is ", hypot, " ", units, "."
end function