how to give sizes in css code example

Example 1: text size in CSS

font-size: 2em;

Example 2: css size

#myID {
  height: 100px; /* Sets the height */
  width: 200px; /* Sets the width */
}
/* or... */
.myClass {
  height: 220px; /* Sets the height */
  width: 40px; /* Sets the width */
}
/* They both work! */