I cannot figure out how to answer this question

I think its is just the circle formula with plugging in the variables and the 2.7 provided but It is incorrect

History Bookmarks Window Help imathas.rationalreasoning.net 51%3 RationalReasoning IMathAS Assessment Q 6 (0/1) function notation - Google Search Q 7 (0/1) Let f be the function that determines the area of a circle (in square cm) that has a radius of r cm. That is, f(r) Q 8 (0/1) represents the area of a circle (in square cm) that has a radius of r cm. Grade: 0/8 Use function notation to respond to each item below. Print Version a. Represent the area (in square cm) of a circle that has a radius of 2.7 cm. pi(7.29) Preview b. Represent how much a circle's area (in square cm) increases when the circle's radius increases from 10.4 to 10.41 cm. Preview c. Represent the total area of 4 circles that each have a radius of 12.4 cm. Preview d. A circle has a radius of 24 cm. A second circle has an area that is 56 square cm more than the first circle. Represent the area of the second circle. Preview Box 1: Enter your answer as an expression. Example: 3x^2+1, x/5, (a+b)/c Be sure your variables match those in the question Box 2: Enter your answer as an expression. Example: 3x^2+1, x/5, (a+b)/c Be sure your variables match those in the question r as an expression. Example: 3x^2+1, x/5, (a+b)/c