Question

assignment
area and circumference review
find the circumference of each circle. round
to the nearest tenth. use 3.14 or $\frac{22}{7}$ for $pi$.
1.
2.
find the area of each figure. round to the
nearest tenth. use 3.14 or $\frac{22}{7}$ for $pi$.
3.
4.
5.

Explanation:

Step1: Calculate circle 1 circumference

Formula: $C=2\pi r$. $r=2.5$ in, $\pi=3.14$
$C=2\times3.14\times2.5 = 15.7$ in

Step2: Calculate circle 2 circumference

Formula: $C=\pi d$. $d=49$ cm, $\pi=\frac{22}{7}$
$C=\frac{22}{7}\times49 = 154.0$ cm

Step3: Calculate circle 3 area

Formula: $A=\pi r^2$. $r=14$ yd, $\pi=\frac{22}{7}$
$A=\frac{22}{7}\times14^2 = \frac{22}{7}\times196 = 616.0$ yd²

Step4: Calculate circle 4 area

Formula: $A=\pi r^2$. $r=3$ m, $\pi=3.14$
$A=3.14\times3^2 = 3.14\times9 = 28.3$ m²

Step5: Calculate semicircle 5 area

Formula: $A=\frac{1}{2}\pi r^2$. $r=15$ ft, $\pi=3.14$
$A=\frac{1}{2}\times3.14\times15^2 = \frac{1}{2}\times3.14\times225 = 353.3$ ft²

Answer:

1. $15.7$ in
2. $154.0$ cm
3. $616.0$ yd²
4. $28.3$ m²
5. $353.3$ ft²