Question

the circumference of a circle is $20\frac{4}{35}$ cm. what is the approximate diameter of the circle? use $\frac{22}{7}$ for $\pi$.

Explanation:

Step1: Convert mixed number to improper fraction

$20\frac{4}{35} = \frac{20\times35 + 4}{35} = \frac{704}{35}$

Step2: Recall circumference-diameter relation

Circumference $C = \pi d$, so $d = \frac{C}{\pi}$

Step3: Substitute values and calculate

$d = \frac{\frac{704}{35}}{\frac{22}{7}} = \frac{704}{35} \times \frac{7}{22} = \frac{704\times7}{35\times22} = \frac{32}{5} = 6.4$

Answer:

$6.4$ cm