13.An archery target has three regions formed by three concentric circ

1.	13.An archery target has three regions formed by three concentric circles as shownin Fig. 11.19. If the diameters of the concentric circles are in the ratio 1: 2:3, thenfind the ratio of the areas of three regions.Fig. 11.19
Answer» The diameter of three concentric circles are in the ratio of 1 : 2 : 3 Let the diameter of the three circles be 1 cm, 2 cm and 3 cmrespectively.So, their radii will also be in the ratio of 1 : 2 : 3. Therefore, the radii of three concentric circle will be1/2 cm, 2/2 cm = 1 cm and 3/2 cm Ratio of their areas =πr₁² : πr₂² : πr₃² = 22/71/21/2 : 22/711 : 22/73/23/2 = 1/4 : 1 : 9/4 So the ratio of their respective ratios is 1/4 : 1 : 9/4 Like my answer if you find it useful!

13.An archery target has three regions formed by three concentric circles as shownin Fig. 11.19. If the diameters of the concentric circles are in the ratio 1: 2:3, thenfind the ratio of the areas of three regions.Fig. 11.19

Answer»

The diameter of three concentric circles are in the ratio of 1 : 2 : 3

Let the diameter of the three circles be 1 cm, 2 cm and 3 cmrespectively.So, their radii will also be in the ratio of 1 : 2 : 3.

Therefore, the radii of three concentric circle will be1/2 cm, 2/2 cm = 1 cm and 3/2 cm

Ratio of their areas =πr₁² : πr₂² : πr₃²

= 22/7*1/2*1/2 : 22/7*1*1 : 22/7*3/2*3/2

= 1/4 : 1 : 9/4

So the ratio of their respective ratios is 1/4 : 1 : 9/4

Like my answer if you find it useful!