Question

The area of a circle is given by the formula A= pie r^2, where r is the radius. If increasing the radius of a circle by 1 inch gives the new circle and area of 100 pie square inches, what in the radius of the original circle?

Answer 1

If you call the radius of the original circle r, then how would you represent the radius of the new circle which is the original circles radius plus 1" ?

Answer 2

I have no idea! @asnaseer

Answer 3

you are told that the radius is increased by 1 inch. so what do you think is the relationship between r and R?

Answer 4

R = r + ?

Answer 5

1?

Answer 6

correct, so we have the increased radius R = r + 1

Answer 7

next, what would be the equation representing the area of the bigger circle?