cant change the width of a button

I am creating a contact us button, but the widthRequest doesn't work on it. However the heightRequest works perfectly.

    var contactUs = new Button {
                Text = "Contact Us",
                TextColor = Color.White,
                BackgroundColor = Color.FromHex ("#FF5722"),
                Font = Font.SystemFontOfSize( 20 ),
                WidthRequest = 05,
                HeightRequest = 35

            };