Sum of internal angles of a 5-point star
<p>The sum of “green” interior angles is 360° (similar for the “blue” angles). Therefore, the sum of the colored angles is 720°.</p>
<p>The sum of interior angles of a triangle is 180°. There are 5 triangles, so the sum of all of their interior angles is 5*180°=900°.</p>
<p>Finally, subtract 720° from 900° to find the sum of interion angles of the star.</p>
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<p>900°-720°=180°</p>
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<p>The sum of the interior angles of a 5-point star is 180°. And it’s true for all 5-point stars.</p>
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