trig
posted by Sergio on .
Both circles have the same center and radius of the larger cirlce is R. if the radius of the msaller circle is 3 units less than R, whic of the following represent the area of the shaded region?

Since diagrams do not show up, I can only guess that they probably showed the shaded area as a ring or resembling a metal washer.
take area of large circle  area of small circle
= pi(R^2)  pi(R3)^2
expand the second term, then simplify.
See if it matches one of the answers.