Question

Which of the following are concave polygons?

• A.
• B.
• C.
• D.

Answer 1

Answer: (B), (C)

The correct options are
B
C

A concave polygon is a polygon in which at least one of the interior angles is greater than ${180}^{\circ }$. In a concave polygon at least one of the diagonals is exterior to the polygon.

In the above figures, figure (ii) and (iii) are concave polygons since both have a diagonal exterior to the polygon.

A convex polygon is a polygon in which all the interior angles are less than ${180}^{\circ }$. In a convex polygon, all the diagonals are interior to the polygon. Figure (i) is a convex polygon since all the interior angles are less than ${180}^{\circ }$.