title: How to color specific region of plot. SageMath
body: <p><a href="https://i.stack.imgur.com/yfiUF.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/yfiUF.png" alt="enter image description here" /></a></p>
  <p>I am starting a project involving Continued Fractions on Hecke triangle surfaces and I would like to color the area over the half circle and between the two vertical lines. How could I do it using sagemath python?</p>
  <pre><code>from sage.plot.line import Line
  var('x')
  e = sqrt(1-x^2)
  f = line([(-1/2, sqrt(3)/2), (-1/2, 3)])
  g = line([(1/2, sqrt(3)/2), (1/2, 3)])
  
  show(plot(e) + g + f, aspect_ratio=1)
  </code></pre>