Answer:
Here's one way to do it
Step-by-step explanation:
Divide the hexagon into triangles, for example, as in the diagram below.
The triangles are all inside the hexagon, so the sum of their interior angles is the sum of those of the hexagon.
The sum of the interior angles of a triangle is 180°.
There are four triangles, so
Sum of interior angles = 4 × 180° = 720°
