Find the areas of the rectangles whose sides are:

(a) 3 cm and 4 cm


(b) 12 m and 21 m


(c) 2 km and 3 km


(d) 2 m and 70 cm


(a) We know that,


Area of rectangle = Length × Breadth


Length of rectangle, l = 3 cm


Breadth of rectangle, b = 4 cm


Therefore,


Area of rectangle = Length × Breadth = 3 × 4 = 12 cm2


(b) We know that,


Area of rectangle = Length × Breadth


It is given in the question that,


Length of rectangle, l = 12 m


Breadth of rectangle, b = 21 m


Therefore,


Area of rectangle = Length × Breadth = 12 × 21 = 252 m2


(c) We know that,


Area of rectangle = Length × Breadth


It is given in the question that,


Length of rectangle, l = 2 km


Breadth of rectangle, b = 3 km


Therefore,


Area of rectangle = Length × Breadth = 2 × 3 = 6 km2


(d) We know that,


Area of rectangle = Length × Breadth


It is given in the question that,


Length of rectangle, l = 2 m


Breadth of rectangle, b = 70 cm = 0.70 m


Therefore,


Area of rectangle = Length × Breadth


= 2 × 0.70


= 1.40 m2


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