question_answer

Find the perimeter of the following rectangles:

Sr. No	Length of Rectangle	Breadth of Rectangle	Perimeter By adding all the sides	Perimeter by 2 \[\mathbf{\times }\] (length \[\mathbf{\times }\] breadth)
(i)	25 cm	12 cm	\[25\,\,cm+12\text{ }cm+\]\[25\text{ }cm+12\text{ }cm\] \[=74\text{ }cm\]	\[=2\times (25\,\,cm\]\[+12\,\,cm)\] \[=2\times (37\,\,cm)\] \[=74cm\]
(ii)	0.5 m	0.25 m
(iii)	18 cm	15 cm
(iv)	10.5 cm	8.5 cm

Answer:

           

Sr. No	Length of Rectangles	Breadth of Rectangle	Perimeter by adding all the sides	Perimeter by 2 \[\times \] (length \[\times \] breadth)
(i)	0.5 cm	0.25 m	= 0.5 m + 0.25 m + 0.5 m + 0.25 m = 1.50 m	= 2 \[\times \] (0.5 m + 0.25 m) = 2 \[\times \] (0.75 m) = 1.50 m
(ii)	18 cm	15 cm	= 18 cm + 15 cm + 18 cm + 15 cm = 66 cm	= 2 \[\times \] (18 cm + 15 cm) = 2 \[\times \] (33 cm) = 66 cm
(iii)	10.5 cm	8.5 cm	= 10.5 cm + 8.5 cm + 10.5 cm + 8.5 cm = 38 cm	= 2 \[\times \] (10.5 cm + 8.5 cm) = 2 \[\times \] (19 cm) = 38 cm
From above example, it is clear the perimeter of a rectangle = 2 \[\times \] (length + breadth)