Question

Q10.The perimeter of a rectangular field is 240 m. If its length is 90 m, find the area of

the rectangle..​

Answer 1

Answer:

Given:-

The perimeter of a rectangle field is 240m. If its length is 90m, find the area of the rectangle.

To Find:-

The area of rectangle.

Note:-

●》Here, for finding Area; we need to find breadth by applying the Perimeter formula i.e. Perimeter of rectangular field = 2 × ( Length + Breadth ).

●》For finding unknown value, known value needs to transposed from its side to another and signs are also changed. For example - Positive becomes Negative, Multiple becomes Divisional.

●》After finding breadth, Area of the rectangle = Length × Breadth.

Solution:-

[ First, Length ]

$\huge\red{Perimeter \ \ of \ \ rectangular \ \ field = 240m}$

$\huge\red{Length = 90m, Breadth = ?, Let \ \ it \ \ be \ \ "x"}$

☆ According to note first point~

▪︎$Perimeter \ \ of \ \ rectangular \ \ field = 2 × ( Length + Breadth )$

▪︎$240m = 2 × ( 90m + x )$

▪︎$240m = 2 × 90m + 2 × x$

▪︎$240m = 180m + 2x$

☆ According to note second point ( transposing )~

▪︎$240m - 180m = 2x$

▪︎$60m = 2x$

▪︎$\dfrac{60m}{2} = x$

▪︎$30m = x$

$\huge\pink{Breadth = x => 30m}$

_______________________________________

[ Now, Area ]

$\huge\red{Length = 90m, Breadth = 30m}$

$\huge\red{\ \ \ \ Area \ \ of \ \ the \ \ rectangle = ?}$

☆ According to note third point~

▪︎$Area \ \ of \ \ the \ \ rectangle = Length + Breadth$

▪︎$Area \ \ of \ \ the \ \ rectangle = 90m × 30m$

☆ After multiplying and m × m = m²~

▪︎$Area \ \ of \ \ the \ \ rectangle = 2,700m²$

$\huge\green{Area \ \ of \ \ the \ \ rectangle = 2,700m²}$

Answer:-

Hence, the area of rectangle = 2,700m².

:)