Check out example codes for "how to change the height of an image in css". It will help you in understanding the concepts better.

Code Example 1

squareImage {
  border: 1px solid #ddd;	/* thickness and color of border */
  border-radius: 4px;		/* edge rounding of border */
  width: 150px;				/* width of image (px or % or auto) */
  height: auto;				/* height of image (px or % or auto) */
}

Code Example 2

div {
  height: 
200px;
  width: 50%;
  background-color: powderblue;
}

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