-step explanation:The rectangle ABCD has 8 such squares. THEREFORE, its area is 8 sq cm. Similarly we can find the areas of the other rectangles by counting the number of squares. We also note the length and breadth of each rectangle and write in the table below:RectangleABCDLMNOPQRSArea8 sq. cm12 sq. cm6 sq. cmLength4 cm4 cm2 cmBreadth2 cm3 cm3 cmLength × Breadth4 cm × 2 cm = 8 cm24 cm × 3 cm = 12 cm22 cm × 3 cm = 6 cm2In each case we observe the length × breadth = Area of the rectangle.Therefore, area of rectangle = length × breadth = l × b sq. unitsFrom the above multiplication, we get the following facts:Length of the rectangle = Area of the RectangleBreadth of the RectangleBreadth of the rectangle = Area of the RectangleLength of the RectangleConsider the following figures:(i)Area of a Rectangle4SaveArea of each small square = 1 sq CMAREA of rectangle in figure 1 by counting the squares = 6 sq. cmArea = 6 square cmLength of rectangle = 3 cmBreadth of rectangle = 2 cmArea = 3 × 2 = 6 sq. cm(ii) Area of a Rectangle4SaveArea of each small square = 1 sq cmArea of rectangle in figure 2 by counting the squares = 10 sq. cmArea = 10 square cmLength of rectangle = 5 cmBreadth of rectangle = 2 cmArea = 5 × 2 = 10 sq. cmHence, area of rectangle = length × breadthA = l × b where, A is the area, l and b are length and breadth of a rectangle.Let us find the area of a rectangle having length 5 cm and breadth 4 cm.Area of Rectangle4SaveFrom the above figure, it is CLEAR that we can divide this rectangle into 20 squares of sides 1 cm each. So, the area = 20 cm2Thus the area of the rectangle = 5 cm × 4 cm = 20 cm2So when we MULTIPLY its length and breadth we get the area of the RECTANGULAR