<h2>Answer:</h2>
The area of the top surface of the washer is: 160.14 square mm.
<h2>Step-by-step explanation:</h2>The top of the surface is in the shape of a annulus with a outer radius of 10 mm and a inner radius of 7 mm ( since the diameter of the hole is: 14 mm and we know that the radius is half of the diameter)
Now, we know that the area of the annulus region is given by:
where R is the outer radius and r is the inner radius.
Here we have:
Hence, we have: