how to get 50 x 50 px by using padding code example

Example 1: html padding

<h2 style="padding-top: 20px; padding-right: 20px; padding-bottom: 20px; padding-left: 20px">London</h2>

Example 2: padding css

.box {
  padding: <padding-top> || <padding-right> || <padding-bottom> || <padding-left>
}