Microsoft Small Basic

Program Listing:

Wid = 200
DrawHeart()
CalcArea()
Controls.TextTyped = TextEnter

Sub DrawHeart
  GraphicsWindow.Clear()
  GraphicsWindow.PenWidth = 0
  GraphicsWindow.BrushColor = "Blue"
  Txt = Shapes.AddText("")
  Shapes.Move(Txt,10,10)
  TB = Controls.AddMultiLineTextBox(GraphicsWindow.Width-170,10)
  Controls.SetSize(TB,160,22)
  GraphicsWindow.BrushColor = "Red"
  C1 = Shapes.AddEllipse(Wid/2,Wid/2)
  C2 = Shapes.AddEllipse(Wid/2,Wid/2)
  S1 = Shapes.AddRectangle(Wid/2,Wid/2)
  GraphicsWindow.BrushColor = "White"
  C3 = Shapes.AddEllipse(Wid/2,Wid/2)
  C4 = Shapes.AddEllipse(Wid/2,Wid/2)
  Shapes.Move(C1,GraphicsWindow.Width/2-Wid/2,GraphicsWindow.Height/2-Wid/2)
  Shapes.Move(C2,GraphicsWindow.Width/2,GraphicsWindow.Height/2-Wid/2)
  Shapes.Move(S1,GraphicsWindow.Width/2-Wid/4,GraphicsWindow.Height/2-Wid/4)
  Shapes.Move(C3,GraphicsWindow.Width/2-Wid/2,GraphicsWindow.Height/2)
  Shapes.Move(C4,GraphicsWindow.Width/2,GraphicsWindow.Height/2)
EndSub

Sub CalcArea
  Area = Math.Round(Wid*Wid-(2*Wid*Wid/16)*Math.Pi-3*((Wid/2)*(Wid/2)-Math.Pi*(Wid/4)*(Wid/4)))
  Shapes.SetText(Txt,"The area of the heart will be "+Area+" square pixels.")
EndSub

Sub TextEnter
  If Text.IsSubText(Controls.GetTextBoxText(TB),Text.GetCharacter(10)) Then
    Wid = Controls.GetTextBoxText(TB)
    DrawHeart()
    CalcArea()
  EndIf
EndSub