Check out example codes for "svg circle". It will help you in understanding the concepts better.

Code Example 1

<svg viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
  <circle cx="50" cy="50" r="50"/>
</svg>

Code Example 2

<svg width="100" height="100">
  <circle cx="50%" cy="50%" r="10" fill="red"/>
</svg>

Code Example 3

<svg viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
  <circle cx="50" cy="50" r="50"/>
</svg>

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