The length of a rectangle is 5cm more than its breadth . if the perimeter of the rectangle is 40 cm , find the dimensions f the rectangle ​

Sagot :

Answer :-

  • 7.5 cm

Solution :-

  • Let the breadth of the rectangle be x cm

  • length of the rectangle = ( x + 5 ) cm
  • perimeter of the rectangle= 2( l + b )

  • 2 ( x + x + 5 ) cm
  • 2 ( 2x + 5 ) cm
  • ( 4x + 10 ) cm

Transpose 10 to RHS

  • therefore ,
  • 4x + 10 = 40
  • 4 x = 40 - 10
  • x = 30 / 4 = 67.5

  • Length of the rectangle = x + 5 = 7.5 + 5 = 12.5
  • Breadth of the rectangle = x = 7.5 cm

Hope it helps !!

The breadth of the rectangle is 7.5cm while the length which is 5cm more than the breadth is 12.5cm.

Breadth b = 7.5cm

Length l = 12.5cm.

What is a rectangle?

A Rectangle is a four sided-polygon with opposite sides parallel and equal to each other, having four angles are right angles.

The perimeter of a rectangle is expressed as;

P = 2( l + b )

Where l is the length and b is breadth.

Given the data in the question;

Let the breadth of the rectangle be represented as y

  • Breadth of the rectangle b = y cm
  • Length of the rectangle l = ( y cm + 5 cm)
  • Perimeter P = 40 cm

To find the dimensions of the rectangle, we substitute our given values into the expression above.

P = 2( l + b )

40 cm = 2( (y cm + 5 cm) + y cm )
40 cm = 2y cm + 10 cm + 2y cm

We collect like-terms

40 cm - 10 cm = 2y cm + 2y cm

30 cm = 4y cm

Divide both sides by 4

30 cm / 4 = 4y cm / 4

y = 7.5cm

Breadth b = y = 7.5cm

Length l = ( 7.5cm + 5cm ) = 12.5cm

The breadth of the rectangle is 7.5cm while the length which is 5cm more than the breadth is 12.5cm.

Breadth b = 7.5cm

Length l = 12.5cm

Learn more about perimeter of rectangles here: https://brainly.com/question/15287805

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