Answer: 
Step-by-step explanation:
The area of a rectangle can be calculated with this formula:

Where "l" is the length and "w" is the width.
You can identify from the figure that the length and the width of this rectangle are:

Then, you need to substitute this lenght and this width into
:

Now, apply Distributive property:

Finally, you need to add the like terms. Then, you get:

2.8a^2=55
a^2=55/2.8
a= square root of 55/2.8
Of course it can. It always is if 'x' is less than 2.