Ans. Some of the common formulas used in mensuration are: - Area of a rectangle = Length x Breadth - Area of a square = side x side - Area of a triangle = 1/2 x base x height - Circumference of a circle = 2 x π x radius - Area of a circle = π x radius^2 - Volume of a cube = side x side x side - Volume of a cylinder = π x radius^2 x height