Question

No Links!! A vinyl record has a circumference of 78.5 cm. What is its area? Use 3.14 for pi and round to the nearest square cm. please dont just give me 3.14 This is 40% of my grade and i'd really appreciate if someone could help me.

Answer 1

Answer:

$\displaystyle A _{ \text{vinyl record }} \approx 490 {cm}^{2}$

Step-by-step explanation:

we are given the circumstances of a vinyl record

we want to figure out the area

in order to do so we should figure out redious first

recall that,

$\displaystyle \rm C = 2\pi r$

given that, C=78.5

thus substitute:

$\displaystyle \rm 78.5= 2\pi r$

divide both sides by 2π:

$\displaystyle r = \frac{78.5}{2\pi}$

we have figured out r now we'll figure out the area

remember that,

$\displaystyle A _{ \text{circle}} = \pi {r}^{2}$

substitute the value of r

$\displaystyle A _{ \text{vinyl record }} = \pi { \bigg(\frac{78 .5}{2\pi} \bigg)}^{2}$

by using calculator we acquire

$\displaystyle A _{ \text{vinyl record }} = 490 {cm}^{2}$