Question

Rupert is copying some files from his computer to a compact disc, like the one shown above.


If the diameter of the compact disc is 120 millimeters, what is the approximate area ignoring the center hole? (Use 3.14 for pi.)

A.

376.8 mm2

B.

11,304 mm2

C.

753.6 mm2

D.

45,216 mm2

Answer 1

Option B: $11,304 \mathrm{mm} ^2$ is the area of the compact disc.

Explanation:

The diameter of the compact disc is $120mm$.

To determine the area of the compact disc, let us substitute the values in the area of the circle formula,

$A=\pi r^2$ where $r=\frac{d}{2}$

Substituting the value of d in $r=\frac{d}{2}$, we get,

$r=\frac{120}{2} =60$

Thus, $r=60$ and $\pi=3.14$. Let us substitute these values in $A=\pi r^2$, we get,

$A=3.14\times(60)^2$

Simplifying, we have,

$A=3.14\times3600$

Multiplying, we get,

$A=11304mm^2$

Thus, the area of the compact disc is $11,304 \mathrm{mm} ^2$

Hence, Option B is the correct answer.