// Get the position and size of a window
Rectangle windowBounds = BFS.Window.GetBounds(windowHandle);

// Get the position and size of the current monitor
Rectangle monitorBounds = BFS.Monitor.GetMonitorBoundsByWindow(windowHandle);

// Check the window's position
if(monitorBounds.Left >= windowBounds.Left) 
{
    // The left side of the window is touching or overlapping the monitor's left edge
}

if(monitorBounds.Right <= windowBounds.Right) 
{            
    // The right side of the window is touching or overlapping the monitor's right edge    
}

if(monitorBounds.Top >= windowBounds.Top)
{
    // The top of the window is touching or overlapping the monitor's top edge
}

if(monitorBounds.Bottom <= windowBounds.Bottom)
{            
    // The bottom of the window is touching of overlapping the monitor's bottom edge    
}