What is the sum of interior angles in a hexagon?

##720^@## i.e. ##4pi## radians

No matter how irregular the hexagon, it can always be dissected into ##4## triangles.

For example:

Each of the ##4## triangles has interior angles summing to ##180^@## - i.e. ##pi## radians.

The interior angles of the hexagon are the sum of the interior angles of the constituent triangles, so sum to:

##4 * 180^@ = 720^@## or ##4pi## radians.