Sum of internal angles of a 5-point star

<p>The sum of &ldquo;green&rdquo; interior angles is 360&deg; (similar for the &ldquo;blue&rdquo; angles). Therefore, the sum of the colored angles is 720&deg;.</p> <p>The sum of interior angles of a triangle is 180&deg;. There are 5 triangles, so the sum of all of their interior angles is 5*180&deg;=900&deg;.</p> <p>Finally, subtract 720&deg; from 900&deg; to find the sum of interion angles of the star.</p> <blockquote> <p>900&deg;-720&deg;=180&deg;</p> </blockquote> <p>The sum of the interior angles of a 5-point star is 180&deg;. And it&rsquo;s true for all 5-point stars.</p> <p><a href="https://medium.com/intuition/sum-of-internal-angles-of-a-5-point-star-e9ea4e183fce"><strong>Website</strong></a></p>