Question

a circular city plaza is surrounded by a row of bricks. the area of the plaza is 1,520 square meters. how long is the row of bricks, to the nearest meter? type the answer in the box. meters

Explanation:

Step1: Find the radius from the area

The area formula of a circle is $A = \pi r^{2}$, where $A = 1520$ square - meters. So, $r^{2}=\frac{A}{\pi}=\frac{1520}{\pi}$, and $r=\sqrt{\frac{1520}{\pi}}$.

Step2: Calculate the circumference

The circumference formula of a circle is $C = 2\pi r$. Substitute $r=\sqrt{\frac{1520}{\pi}}$ into the formula: $C = 2\pi\sqrt{\frac{1520}{\pi}}=\sqrt{4\pi^{2}\times\frac{1520}{\pi}}=\sqrt{4\pi\times1520}=\sqrt{6080\pi}$.
Using $\pi\approx3.14$, we have $C=\sqrt{6080\times3.14}=\sqrt{19091.2}\approx138$.

Answer:

138