Answers for "border radius for a button"

border radius circle button

.btn {
  height: 300px;
  width: 300px;
  border-radius: 50%;
  border: 1px solid red;
}

how to make a rounded button

<Style TargetType="Button" x:Key="RoundButton">
    <Style.Resources>
        <Style TargetType="Border">
            <Setter Property="CornerRadius" Value="5" />
        </Style>
    </Style.Resources>
</Style>