the complete question in the attached figure
we know that
[the approximate area of the remaining cardboard]=(area of rectangle) - 2(area of circle)
area of rectangle=14 cm* 18 cm------> 252 cm²
area of a circle=pi*r²
r=2/1----> 1 cm
area=pi*1²-----> 3.14 cm²
[the approximate area of the remaining cardboard]=252- 2*3.14
=245.72-------> 246 cm²
the answer is
246 cm²