Question

Given each of the following areas, what would be the radius of each circle? a. A = 530.66 m2 b. A = 907.46 sq. ft. c. A = 379.94 sq. mi. d. A = 1962.5 cm2

Answer 1

Area for a circle is $A= \pi r^2$.  We will fill in each area and then solve for the radius.  $530.66m^2= \pi r^2$ and $\frac{530.66m^2}{3.14}=r^2$.  ∴$169=r^2$ and r = 13.  For b, $907.46ft^2= \pi r^2$ and $\frac{907.46ft^2}{3.14}=r^2$.  $289=r^2$, ∴ r = 17.  For c, $379.94mi^2= \pi r^2$, and $\frac{379.94mi^2}{3.14}=r^2$.  ∴, $121=r^2$ and r = 11.  For d, $1962.5cm^2= \pi r^2$, and $\frac{1962.5cm^2}{3.14}=r^2$.  ∴, $625=r^2$ so r = 25.  And there you have it!