MuPAD Pro Computing Essentials - Examples 

Example 5.1 - Heron Formula

The very simple Heron's formula to calculate the area of a triangle with given lengths of all three sides deserves a bit more of your attention. Here you can experiment a bit and see what you need to take care with while writing procedures. 

• heron := proc(a,b,c)
  local s;
  begin
     if a<0 or b<0 or c<0 or (a-b-c)*(b-a-c)*(c-a-b)>0
     then
        print("This is not a real triangle")
     else
        s := (a + b + c)/2;
        return(sqrt(s*(s - a)*(s - b)*(s - c)));   
     end
  end:

Now you can try to see what you get for various input data:

• heron(3,4,5);
• heron(3,3,7);
• heron(1,-1,0);