Question

If the radius of a sphere is doubled, then what is the ratio of surface area of original sphere to newly formed sphere ?

Answer 1

Answer: 1:4.

Explanation:

SA of a sphere w/ radius r = 4πr²

Let the old radius be = R

∴ Old SA = 4πR²

Now, New radius = 2R

∴ New SA = 4π(2R)² = 16πR²

Hence,

ratio = SA of old sphere / SA of new sphere = 4πR²/16πR² = 1/4 = 1:4.

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Answer 2

Answer:

Hope it helps you :)

Step-by-step explanation:

The increase in surface area is 300% when the radius of a sphere is doubled. Therefore it is concluded that if the radius of a sphere is doubled then the ratio of their surface area is 4 times the old area. To know more about surface area, visit: The ratio of the surface area of two-sphere is 3: 5.