The diameter of a circle x is 18 cm the diameter of circle y is 31 cm which circle has the greater area and by how much you 3.14 for pie

Area of a circle = (pi)(radius squared)
A of Circle X= (3.14)(18cm/2)squared

We need to divide the diameter in half to get the radius.
A of Circle X= (3.14)(9) squared
A of Circle X= (3.14)(81)
A if Circle X= 254.34 cm

A of Circle Y= (3.14)(31cm/2)squared

We need to divide the diameter in half to get the radius.
A of Circle Y= (3.14)(15.5) squared
A of Circle Y= (3.14)(240.25)
A if Circle Y= 754.39 cm

Find the difference in Area:
=Circle Y - Circle X
=754.39 - 254.34
=500.05 cm difference

Circle Y has the greater area of 754.39. It it greater than Circle X by 500.05 cm