Answer: 72 cm²
Step-by-step explanation: lets take the width as x and length as 2x as length is twice the width= perimeter of rectangle is 2*(l+b)=36cm
So, 2×(2x+x)=36cm
2×3x=36cm
6x=36cm
X=36/6:6cm( width, since width was taken as x)
Length= 2x: 2×6=12cm
So area of the rectangle is( l*b):
12×6= 72cm²