Question

Calculate the area of the circle whose diameter is 6 km. Note: you will need the radius. Please round to the nearest square kilometer.

my answer was
first to find the radius we divide the diameter in half

6/2= 3

so the radius is 3 so now we times that by



x 32 =



then i simlifly it to

9



then i subsitute 3.14 for



9 x 3.14 = 28.2



the area is exactly 9 or about 28.8 centimeters

but my teacher says i need to rounded and the units should be squared