Hello!
To find the area of a circle you use the equation

r is radius which is half the diameter
r = 2.6 / 2
r = 1.3
Put in the values you know

Square the number

The answer is

or ≈5.31
Hope this helps!
V=4/3*pi*r^3
dV/dr=4/3*pi*d(r^3)/dr =4/3*pi*(3*r^2)=4*pi*r^2
Answer:
Step-by-step explanation: Lucy is correct because all of the squares are filled, and therefore instead of 1 square filled, 8 are, this is why lucy <em>is</em> correct :)