Question

22. If length of a rectangle is 5 less than 3 times it's breadth and perimeter of the rectangle is 22m, then
area of the rectangle is
[ ]
a) 28m?
b) 14 m²
c) 11m
d) 21 m²
umber is​

Answer 1

Let l and b be the length and breadth of rectangle.

According to the question-

l=3b−5.....(1)

Perimeter of rectangle =22m(Given)

As we know that the perimeter of rectangle is given as-

P=2(l+b)

Therefore,

2(l+b)=22

l+b=11

(3b−5)+b=11(from (1))

4b=11+5

⇒b=416=4m

Substituting the value of b in eqn(1), we have

l=3×4−5=7m

Therefore,

Area of rectangle =l×b=7×4=28m2

Hence the area of rectangle is 28m2.