High School

(p) The length of a rectangle is (x+3) metres and the breadth is (x-2) metres. If the perimeter is 38 metres, calculate the value of x.

(q) What is the length of a rectangle if its breadth is 12 metres and the area is 180 m²?

Answer :

Let's tackle each part of the question step by step.

(p) Finding the value of [tex]x[/tex]:

Given:


  • Length of the rectangle = [tex]x + 3[/tex] metres

  • Breadth of the rectangle = [tex]x - 2[/tex] metres

  • Perimeter of the rectangle = 38 metres


We know that the formula for the perimeter [tex]P[/tex] of a rectangle is:
[tex]P = 2 \times (\text{Length} + \text{Breadth})[/tex]

Substitute the given values into the formula:
[tex]38 = 2 \times ((x + 3) + (x - 2))[/tex]

Simplify the expression inside the parentheses:
[tex]38 = 2 \times (2x + 1)[/tex]

Now distribute the 2 to terms inside the parentheses:
[tex]38 = 4x + 2[/tex]

Subtract 2 from both sides to isolate terms with [tex]x[/tex]:
[tex]36 = 4x[/tex]

Divide by 4 to solve for [tex]x[/tex]:
[tex]x = 9[/tex]

(q) Finding the length when breadth and area are given:

Given:


  • Breadth of the rectangle = 12 metres

  • Area of the rectangle = 180 m²


We know that the formula for the area [tex]A[/tex] of a rectangle is:
[tex]A = \text{Length} \times \text{Breadth}[/tex]

Substitute the given values into the formula:
[tex]180 = \text{Length} \times 12[/tex]

Solve for Length:
Divide both sides by 12:
[tex]\text{Length} = \frac{180}{12} = 15 \, \text{metres}[/tex]

Therefore, the value of [tex]x[/tex] is 9, and the length of the rectangle when its breadth is 12 metres and the area is 180 m² is 15 metres.