Question

The area of a rectangle is 168 sq.cm and it's length is 15cm. Find it's breadth and perimeter​

Answer 1

Provided that:

• Area of rectangle = 168 cm sq.
• Length = 15 cm.

To calculate:

• Perimeter
• Breadth

Solution:

• Perimeter = 52.4 cm
• Breadth = 11.2 cm

Using concepts:

• Area of rectangle formula
• Perimeter of rectangle formula

Using formulas:

• A = L × B
• P = 2(l+b)

Required solution:

~ Firstly by using area of rectangle formula let us find out the breadth of the given rectangle.

⇒ Area of rectangle = L × B

⇒ 168 = 15 × B

⇒ 168/15 = B

⇒ 11.2 = B

⇒ B = 11.2 cm

⇒ Breadth = 11.2 cm

~ Now by using perimeter of rectangle formula let us find out the perimeter!

⇒ Perimeter of rectangle = 2(l+b)

⇒ Perimeter of rectangle = 2(15+11.2)

⇒ Perimeter of rectangle = 2(26.2)

⇒ Perimeter of rectangle = 2 × 26.2

⇒ Perimeter of rectangle = 52.4 cm

Verification:

~ Now let us verify our results.

Let us verify the magnitude of breadth, as if magnitude of breadth is correct then if we are done with correct calculations then perimeter's magnitude is also correct.

⇒ Area of rectangle = L × B

⇒ 168 = 15 × 11.2

⇒ 168 = 168

⇒ L.H.S = R.H.S

• Henceforth, verified!

$\begin{gathered} \sf 15 \: cm \: \: \: \: \: \: \: \: \: \: \: \\ \begin{gathered}\begin{gathered}\boxed{\begin{array}{}\bf { \red{}}\\{\qquad \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: }{}\\ { \sf{ }}\\ { \sf{ }} \\ \\ { \sf{ }}\end{array}}\end{gathered}\end{gathered} \sf 11.2 \: cm\end{gathered}$

Answer 2

Area= l*b
168=15*b
B=168/15
b=11.2cm

Perimeter = 2(l+b)
P=2(15+11.2)
P=52.5