Question

find the area of a circle with a circumference of 31.4 units.
□ units²
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Explanation:

Step1: Recall circumference formula

The circumference of a circle is $C = 2\pi r$. We know $C=31.4$, use $\pi \approx 3.14$.

Step2: Solve for radius $r$

Rearrange formula: $r = \frac{C}{2\pi}$
$r = \frac{31.4}{2\times3.14} = 5$

Step3: Recall area formula

Area of a circle is $A = \pi r^2$.

Step4: Calculate the area

Substitute $r=5$ and $\pi\approx3.14$:
$A = 3.14\times5^2 = 3.14\times25$

Answer:

78.5 units$^2$