This document discusses perimeter and area of quadrilaterals. It defines a quadrilateral as a polygon with four sides and explains that perimeter is the distance around a two-dimensional shape. It presents formulas to calculate the perimeter and area of quadrilaterals by breaking them into two triangles. The perimeter formula is the sum of the distances of all the sides and the area formula is half the product of the distance and sum of the bases of the two triangles.