Proof that the Quadrilateral Angle Sum is 360 Degrees

After discussing the triangle angle sum proof, we now discuss the quadrilateral angle sum proof. The proof of this theorem comes from the fact that we can divide a quadrilateral into two triangles by drawing a diagonal. Since each triangle angle sum is 180°, the sum of the interior angle of the quadrilateral is therefore 360°.

Watch the video above to know the details of its proof.