Question

The area of the blue region is about ___ square cm. Use 3.14 for π.

Answer 1

SOLUTION

Step 1 :

In this question, we are asked to find the area of the Blue Region.

To achieve this,

We need to find the Radius of the Big Circle, R = 10 cm + 5 cm = 15 cm

We need to find the Radius of the Small Circle, r = 5 cm

Step 2 :

We need to use the formulae :

$\begin{gathered} \pi\text{ }R^2\text{ - }\pi r^2 \\ (\text{ to find the area of the Blue/ Shaded Region )} \\ \pi\text{ = 3. 14} \\ R\text{ = 15 cm} \\ \text{r = 5 cm} \end{gathered}$

$\begin{gathered} (\text{ 3. 14 x 15cm x 15 cm ) - ( 3. 14 x 5 cm x 5cm )} \\ =706.5cm^2-78.5cm^2 \\ =628cm^2 \end{gathered}$

CONCLUSION :

The area of the Blue region is about 628 square cm.