Joke Collection Website - Talk about mood - Please explain in at least two different ways that the sum of the four internal angles of a quadrilateral is 360.

Please explain in at least two different ways that the sum of the four internal angles of a quadrilateral is 360.

(1) Two triangles are obtained by taking a vertex of a quadrilateral as a diagonal. According to the triangle interior angle sum theorem, the quadrilateral interior angle sum is 2* 180=360 degrees.

(2) If any point on one side of a quadrilateral is diagonal, three triangles can be obtained, and the sum of the internal angles of the quadrilateral is 3* 180- 180=360 degrees.

(3) Four triangles can be obtained by connecting any point inside the quadrilateral with vertices, and the sum of the internal angles of the quadrilateral is 180*4-360=360 degrees.

(4) Make parallel lines later.

(5) According to the formula (n-2)* 180, because it is a quadrilateral, (4-20)* 180=360 degrees.