1. The problem is to understand the different types of quadrilaterals. 2. A quadrilateral is a polygon with four sides and four angles. 3. The main types of quadrilaterals include: - Square: all sides equal, all angles 90° - Rectangle: opposite sides equal, all angles 90° - Rhombus: all sides equal, opposite angles equal - Parallelogram: opposite sides equal and parallel, opposite angles equal - Trapezoid (US) / Trapezium (UK): at least one pair of parallel sides - Kite: two pairs of adjacent sides equal 4. Each type has specific properties and formulas for area and perimeter. 5. Understanding these helps in solving geometry problems involving quadrilaterals.