A rectangular plot of land measures 45m × 30m. A boundary wall of height 2.4m is built all around the plot at a distance of 1m from the plot. Find the area of inner surface of the boundary wall

Open in App

Solution

If you are wondering about how the four wall formula has been used. Consider the outer rectangle and say we are drawing the wall over it. You would agree the length all around is the perimeter and I hope you know that the perimeter of rectangle contains 4 components, there are 2 lengths and 2 breadths that is why the formula is l+b+l+b or 2(l+b).
If you are going to multiply each part by height. We get lh + bh + lh+ bh. This is same as h (l+b+l+b) = h(2l+2b) = 2h(l+b). If you know factorization you would be able to understand how h is factored out as a common factor.
I hope the solution is much more clear now.

Suggest Corrections

Similar questions

Q. A rectangle plot of land measures

45

\times

30

m. A boundary wall of height

2.4

m is built all round the plot at a distance of

1

m from the plot. Find the area of the inner surface of the boundary wall.

Q. The house is built on a rectangular plot of land,

21 m

17 m,

.Calculate the area of plot.

The area of a square plot is $6084 m^{2}$ . Find the length of the wire which can go four times along the boundary of the plot.

Q. The area of a square plot is 6084

m^{2}

. Find the length of the wire which can go four times along the boundary of the plot

What will be the cost of gardening 1 metre broad boundary around a rectangular plot having a perimeter of 340 metres at the rate of Rs.10 per square metre?

Join BYJU'S Learning Program