The paper is 16 cm by 34 cm to start with, so we started with area
.. (16 cm)*(34 cm) = 544 cm^2
A circle of diameter 16 cm has been removed. The area of that circle is
.. π*(d/2)^2 = 3.14*(16 cm/2)^2 = 200.96 cm^2
Then the area of the paper that remains is
.. 544 cm^2 -200.96 cm^2
.. = 343.04 cm^2