Answer:
540°
Step-by-step explanation:
When you have a polygon (shape with 3+ sides), you can split the shape into the lowest number of triangles and use that to calculate the interior angles of the shape. Thus works because triangles have angles that always add up to 180°
A Pentagon can be split into 3 triangles minimum, which means you have 180 + 180 + 180. Or...
180 x 3 = 540
