A trapezoid, also known as a trapezium in some regions, is a four-sided polygon (quadrilateral) that has at least one pair of parallel sides. The non-parallel sides are called legs, and the angles adjacent to each leg can vary. Trapezoids can be classified into different types, such as isosceles trapezoids, where the non-parallel sides are of equal length. The area of a trapezoid can be calculated using the formula: Area = (1/2) × (base1 + base2) × height.