Thanks for your response.
I've read these responses.
and quote the passage by MEB:
”With the Polygon Marquee Tool tool selected, check if the last icon on the top right on the context toolbar (looks a triangle) has an outline around the circle. If so the antialiasing is enabled. If not, tap the icon to turn the antialiasing on - the outline around the circle should appear.”
If that's what you mean...
I'm really sorry that I don't understand.
I couldn't find a icon on the top right on the context toolbar and looks a triangle...
If you can mark the possible answers with pictures,
maybe you can help the stupid me.
My english is not so good, but I hope you understand what I write.
Thanks again for your response!