What do a quadrilateral and a pentagon have in common?

A quadrilateral is a 4 sided polygon, while a pentagon is a 5 sided polygon.

Answer: A quadrilateral and a pentagon have in common are that they both are closed polygons and the sum of their exterior angles is 360°.

Both quadrilateral and pentagon are two-dimensional closed shapes.

Explanation:

A quadrilateral is a closed polygon that is obtained by joining four points among which any three points are non-collinear. Hence it is a 4-sided polygon.

The pentagon is a 5-sided polygon formed by joining 5 vertices and no three vertices are collinear.

Also, we know that the sum of exterior angles of any polygon is 360°.

Thus, what quadrilateral and a pentagon have in common is that they both are closed polygons and the sum of their exterior angles is 360°.