Canvas

<Canvas Background="Lavender">

        <Button Background="AliceBlue" Content="Top 20 Left 40" 

                     Canvas.Top="20" Canvas.Left="40"/>

        <Button Background="LightSkyBlue" Content="Top 20 Right 20" 

                     Canvas.Top="20" Canvas.Right="20"/>

        <Button Background="Aquamarine" Content="Bottom 30 Left 20" 

                     Canvas.Bottom="30" Canvas.Left="20"/>

        <Button Background="LightCyan" Content="Bottom 20 Right 40" 

                     Canvas.Bottom="20" Canvas.Right="40"/>

</Canvas>