Check.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

    <Geometry x:Key="CheckOK_Geom">M9,20.42L2.79,14.21L5.62,11.38L9,14.77L18.88,4.88L21.71,7.71L9,20.42Z</Geometry>
    <Geometry x:Key="CheckNO_Geom">M20 6.91L17.09 4L12 9.09L6.91 4L4 6.91L9.09 12L4 17.09L6.91 20L12 14.91L17.09 20L20 17.09L14.91 12L20 6.91Z</Geometry>

    <Viewbox x:Key="CheckOK" Width="24" Height="24">
        <Canvas Width="24" Height="24">
            <Path Data="{DynamicResource CheckOK_Geom}" Fill="Black" />
        </Canvas>
    </Viewbox>

    <Viewbox x:Key="CheckNO" Width="24" Height="24">
        <Canvas Width="24" Height="24">
            <Path Data="{DynamicResource CheckNO_Geom}" Fill="Black" />
        </Canvas>
    </Viewbox>
    
</ResourceDictionary>