If the interior angle of a regular polygon is 144°, then what is the number of its sides?

Given here are some figures.



Classify each of them on the basis of the following.
(a) Simple curve
(b) Simple closed curve
(c) Polygon
(d) Convex polygon
(e) Concave polygon

If the exterior angle of a regular polygon is 72°, then what is the number of sides of the polygon?

The diagonals of a rhombus bisect each other at __________ .

If an exterior angle of a regular polygon is 45°. then find the number of its sides.