Mensuration Practice Test 5

Let radius = 7 cm.
Circumference = $2\times \frac{22}{7}\times 7$ = 44 cm
New circumference = 44 + $\frac{5}{100}\times 44$
= 46.2 cm.
Radius ⇒ $2\times \frac{22}{7}\times \mathit{r}$ = 46.2
r = 46.2 × $\frac{7}{22}\times \frac{1}{2}$
r = 7.35 cm
Area = $\frac{22}{7}\times 7\times 7$ = 154 $\mathit{c}{\mathit{m}}^2$
New area = $\frac{22}{7}\times 35\times 7.35$ = 169.785
Increased percentage of area = $\frac{15.785}{154}\times 100$ = 10.25 %