Find the circumference of a circle whose area is 60pi cm^2.A. [tex]2 \sqrt{15\pi } \: cm[/tex]B. [tex]4 \sqrt{15\pi} \: cm[/tex]C. [tex]30\pi \: cm[/tex]D. [tex]900\pi \: cm[/tex]
Accepted Solution
A:
Answer: none of the offered choices is correct [tex]circumference=4\pi\sqrt{15}\,\text{cm}[/tex]Step-by-step explanation:We can use the area equation to find the radius of the circle, then use that to find the circumference. A = πr² 60π = πr² 60 = r² . . . . . . . divide by π √60 = 2√15 = r . . . . take the square rootNow, the circumference is given by ... C = 2πr C = 2π(2√15) = 4π√15 . . . . cm_____If the area were 60 cm², answer choice B would be correct. Since it is 60π cm², no answer choice is correct.