Chapter 1 - Introduction to Physics - Problems and Conceptual Exercises - Page 15: 18

(a) $A=648.7~m^{2}$ (b) $A=45~m^{2}$

(a) We can find the required area of the circle as $A=\pi r^2$ We plug in the known values to obtain: $A=3.1416(14.37m)^2$ $A=648.7m^2$ (b) We know that $A=\pi r^2$ We plug in the known values to obtain: $A=3.1416(3.8m)^2$ $A=45m^2$