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