Question

Find the area of circle having 176cm circumference.With step by step explanation.plz​

Answer 1

Answer:

$\huge\boxed{A=784\pi\ cm^2\approx2464\ cm^2}$

Step-by-step explanation:

The formula of a circumference of a circle:

$C=2\pi r$

r - radius

The formula of an area of a circle:

$A=\pi r^2$

r - radius

We have C = 176cm. Substitute to the formula and calculate the radius r:

$2\pi r=176\qquad|\text{divide both sides by}\ 2\pi\\\\r=\dfrac{176}{2\pi}\\\\r=\dfrac{88}{\pi}\qquad|\text{use}\ \pi\approx\dfrac{22}{7}\\\\r=\dfrac{88}{\frac{22}{7}}\\\\r=88\cdot\dfrac{7}{22}\\\\r=4\cdot7\\\\\boxed{r=28(cm)}$

Calculate the area:

$A=\pi\cdot28^2=784\pi\approx784\cdot\dfrac{22}{7}=112\cdot22=2464(cm^2)$

According to the moderator, I should take $\pi\approx3.14$. You can do it like that. In my opinion, my solution is correct.