Unless there is a given measurement of the lengths of the sides of the figure (ex. cm., mm., in.) you would say units, and put a little 2 as an exponent because you need to write square units.
surface area
A square with an area of 400 square units has a perimeter of 80 units.
A square with a side length of 9 units has an area of 81 square units.
A square with an area of 3,600 square units has side lengths of 60 units each.
h.8 square units
35 square units is the area.
A circle with an area of 100.53 square units has a circumference of 35.542 units.
The size of that area is known as the "area" of the figure.
square units
That's the figure's "area".
Is its area.
the answer is area
area
It is the area of the figure.
area
The area of a 3 dimensional figure
This would be the area.