Question

2. An archery target has three regions formed by three concentric circles. If the diameters of concentric circles are in the ratio 1:2:3 then find the ratio of the areas of three regions.

Answer 1

Solution:-

Let the diameter of the three concentric circles be 'x, 2x and 3x.
We know that if the diameter ratio is same then the radius ratio will also be the same. So, the radius will be x/2, 2x/2 = x and 3x/2 
So, ratio of the area = πr₁² : πr₂² : πr₃²
= (1/2)² : (1)² : (3/2)
= 1/4 : 1 : 9/4
So, the ratio of their respective areas is 1/4 : 1 : 9/4
Answer.