Answer:
200ft^2
Step-by-step explanation:
From the first sentence;
L = 2B
Perimeter of a rectangle = 60ft
P = 2[ L +B ]
substitute as follows;
60 = 2( 2B + B)
60 = 2(3B)
60 = 6B
B = 10ft
To find L
L = 2B
L = 2*10
L = 20 ft
Area of a rectangle = LB
= 20×10
=200ft^2