A malted milk ball with a radius of ¼" (0.25 in) is coated with chocolate. What is the surface area of the chocolate? Ignore the thickness. Leave your answer in terms of π.

Question

zepdrix · Answer

The surface area of a sphere is given by:$$\Large A=4\pi r^2$$

In this problem our radius is given to be $\large r=\dfrac{1}{4}$.

So just plug that in and solve for A! :)
They told us they want the answer in `terms of pi`. So do not multiply out the pi as 3.14 or anything like that. Leave it as $\large \pi$.

$$\Large A=4\pi \left(\frac{1}{4}\right)^2$$

anonymous · Answer

I got .7853

zepdrix · Answer

So when we square 1/4 we get,$$\Large A=4\pi\left(\frac{1}{16}\right)$$Let's multiply the 4 and 1/16,$$\Large A=\frac{4}{16}\pi \qquad\to\qquad A=\frac{1}{4}\pi$$This is in terms of pi. See how I left the $\large \pi$ icon?
You got the correct answer, but don't multiply out the pi to give you a decimal! :)

anonymous · Answer

So it would just be $$A=1/4\Pi $$ ?

zepdrix · Answer

yes :)

anonymous · Answer

Awesome! Thanks! You rock!!!(: