Circumference=2*pi*r or pi*d so if its 16pi you know that your diameter is 16 wich means your radius is 8 because d/2 is your radius. plug the 8 into the area formula wich gives you the formula pi*8^2. 8squared is 64. 64 times pi is 201. <span>or 64pi wich is the area of the same circle with the circumfernce of 16pi
</span>
total units of ration = 4 +7=11
so, ratio would be (4*33)/11 : (7*33)/11
12 : 21 is the answer.
Did you understand?
