 Hello and welcome to the session. Let us discuss the following question. It says, find the radius of a sphere whose surface area is 154 centimeter square. Now the formula for the surface area of sphere is 4 pi r square, where r is the radius of the sphere and the value of pi is 22 upon 7. Now we have to find the radius of the sphere. Let us now move on to the solution. We are given that the surface area of sphere is equal to 154 centimeter square that is 4 pi r square is equal to 154 centimeter square. So this implies r square is equal to 154 upon 4 pi that is r square is equal to 154 upon 4 into pi which is 22 upon 7 that is 154 into 7 upon 88 and it is equal to 12.25. So r square is equal to 12.25. This implies r is equal to under the root of 12.25 that implies r is equal to 3.5. Hence the radius is 3.5 centimeter. So this completes the question. Bye for now. Take care. Have a good day.