Question

For rectangle: length=5cm,breadth=?,area=?,perimeter=24cm

Answer 1

2(l+b)=24
5+b=12
b=7 cm
area = l*b
        = 5*7
        = 35 cm^2   

Answer 2

From the perimeter;

P=2l+2b
24=2×5+2b
24=10+2b
2b=14
b=14/2
b=7

Now,l=5 b=7

Area=l×b
=5×7 cm^2
=35 cm^2