area and perimeter

Question

The perimeter of a rectangle is equal to the perimeter of a square of side 8 cm.The length of the rectangle is 12 cm. Find the breadth.

Answer 1

The perimeter of a square is four times the length of one side:     P = 4s

   P = 4(8) = 32

 

The perimeter of a rectangle is twice the length plus twice the width (breadth):  P = 2L + 2W

   It is the same as the given square (32), so

     32 = 2(12) + 2W                [plug in 32 and 12]

      32 = 24 + 2W

       8 = 2W              [subtract 24 from both sides]

       4 = W            [divide both sides by 2]

     The breadth (width) id 4 cm.

 

Check:

  Is   32 = 2(12) + 2(4)   ?

        32 = 24 + 8   ?

         32 = 32  ?yes

  so each side