Question

Given a rectangle of width w and height h. and a coordinate x,y in that rectangle I would like to identify which triangle I am within.

i.e. the function should take parameters(x,y) and return a,b,c,d or a zero based number representing that triangle index i.e. (0=A,1=B,2=C,3=D) if they are in that order.

I think this would be something like >= the formula of the red line and >= the formula of the green line?

I’d like to implement this in VB.NET

Answer 1

aboveRed = x*h > y*w;
aboveGreen = (w-x)*h > y*w;
if (aboveRed)
{
    if (aboveGreen) return "C"; else return "B";
}
else
{
    if (aboveGreen) return "D"; else return "A";
}