Answer:
pentagon
Explanation:
The sum of the interior angles of a triangle (in a plane) is 180°, the sum of the interior angles of a quadrilateral is 360°, the sum of the interior angles of a pentagon is 540°, the sum of the interior angles of a hexagon is 720°, and in general, the sum of the interior angles of an n-gon (a polygon with n sides) is 180°× (n-2).
JUST SOME EXTRA POINT YK