Answers for "elevated button radius"

flutter elevated button radius

style: ButtonStyle(
  shape: MaterialStateProperty.all<RoundedRectangleBorder>(
    RoundedRectangleBorder(
      borderRadius: BorderRadius.circular(18.0),
      side: BorderSide(color: Colors.red)
    )
  )
)

border radius circle button

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