1. The problem is to understand what polygons are and their basic properties. 2. A polygon is a closed plane figure with at least three straight sides and angles. 3. The sum of the interior angles of a polygon with $n$ sides is given by the formula: $$\text{Sum of interior angles} = (n-2) \times 180^\circ$$ 4. For example, a triangle ($n=3$) has interior angles summing to: $$(3-2) \times 180^\circ = 180^\circ$$ 5. A quadrilateral ($n=4$) has interior angles summing to: $$(4-2) \times 180^\circ = 360^\circ$$ 6. This formula helps in finding unknown angles or verifying polygon properties. 7. Polygons can be regular (all sides and angles equal) or irregular. 8. Understanding polygons is fundamental in geometry and many applications.