title: How to draw a semicircle using matplotlib
body: <p>I want to draw a semicircle using matplotlib. </p>
  
  <p>Here I have a court</p>
  
  <pre><code>import numpy as np
  import matplotlib.pyplot as plt
  x_asix = np.array([0,0,100,100, 0])
  y_asix = np.array([0,100,100,0, 0])
  x_coordenates = np.concatenate([ x_asix])
  y_coordenates = np.concatenate([y_asix])
  
  plt.plot(x_coordenates, y_coordenates)
  </code></pre>
  
  <p>See image here:</p>
  
  <p><a href="https://i.stack.imgur.com/iGMse.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/iGMse.png" alt="Field"></a> </p>
  
  <p>I want to add one semicircle that stars at point (0,50) with radius = 10. 
  The result should be something like this:</p>
  
  <p><a href="https://i.stack.imgur.com/OQ36y.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/OQ36y.png" alt="Expected output"></a></p>