С клавиатуры вводятся координаты точки x, y. Определить, какой из областей: заштрихованной (№1) или незаштрихованной (№2

      if (y <= -x + 1 && y >= 0 && x >= 0 || y >= x && y <= 0 && x >= -1)
        // выводим 1
      else
        // выводим 2

//---------------------------------------------------------------------------
 
#include <vcl.h>
#pragma hdrstop
 
#include "Unit1.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
    : TForm(Owner)
{
}
//---------------------------------------------------------------------------
const shift = 30, shiftX = 5, shiftY = 5;
double width, height, x1, x2, y1, y2, difX, difY;
 
void __fastcall TForm1::ButtonClick(TObject *Sender)
{
  width = Image->Width - 2 * shift, height = Image->Height - 2 * shift;
  x1 = SpinEditX1->Text.ToIntDef(-10), x2 = SpinEditX2->Text.ToIntDef(10);
  y1 = SpinEditY1->Text.ToIntDef(-10), y2 = SpinEditY2->Text.ToIntDef(10);
  difX = width / (x2 - x1), difY = height / (y2 - y1);
 
  Image->Canvas->Pen->Color = clSilver;
  Image->Canvas->Pen->Width = 1;
  Image->Canvas->Brush->Style = bsSolid;
 
  Image->Canvas->FillRect(Image->Canvas->ClipRect);
 
  int i;
  for (i = 0; i <= x2 - x1; i++)
  {
    Image->Canvas->MoveTo(shift + difX * i, shift         );
    Image->Canvas->LineTo(shift + difX * i, shift + height);
    Image->Canvas->TextOutW(shift - shiftX + difX * i, shift + shiftY + height, String(i + x1));
  }
  for (i = 0; i <= y2 - y1; i++)
  {
    Image->Canvas->MoveTo(shift,         height + shift - difY * i);
    Image->Canvas->LineTo(shift + width, height + shift - difY * i);
    Image->Canvas->TextOutW(shift - 4 * shiftX, height + shift - shiftY - difY * i, String(y1 + i));
  }
 
  Button2->Enabled = 1;
  Button3->Enabled = 1;
}
//---------------------------------------------------------------------------
void __fastcall TForm1::Button2Click(TObject *Sender)
{
  Image->Canvas->Pen->Color = clBlue;
  Image->Canvas->Pen->Width = 3;
  Image->Canvas->Brush->Style = bsClear;
 
  double x[2] = {shift + difX * (-x1 + LEx1->Text.ToDouble()), shift + difX * (-x1 + LEx2->Text.ToDouble())},
         y[2] = {shift + height - difY * (-y1 + LEy1->Text.ToDouble()), shift + height - difY * (-y1 + LEy2->Text.ToDouble())};
 
  switch (ComboBox->ItemIndex)
  {
    case 0:
      Image->Canvas->MoveTo(x[0], y[0]);
      Image->Canvas->LineTo(x[1], y[1]);
      break;
    case 1:
      Image->Canvas->Rectangle(x[0], y[0], x[1], y[1]);
      break;
    case 2:
      Image->Canvas->Ellipse(x[0], y[0], x[1], y[1]);
      break;
  }
}
//---------------------------------------------------------------------------
void __fastcall TForm1::Button3Click(TObject *Sender)
{
  Image->Canvas->Pen->Width = 1;
  Image->Canvas->Brush->Style = bsSolid;
 
  double step = 0.01, R = 2;
 
  for (double x = -R; x <= R; x += step)
    for (double y = -R; y <= R; y += step)
    {
      double i = shift + difX * (x - x1);
      double j = shift + height - difY * (y - y1);
 
      if (y <= -x + 1 && y >= 0 && x >= 0 || y >= x && y <= 0 && x >= -1)
        Image->Canvas->Pixels[i][j] = clGreen;
    }
}
//---------------------------------------------------------------------------