What is the area of a circle that has a diameter of 4.2 cm?

2 Answers
Jul 31, 2018

Area of a circle

Explanation:

#A=pitimes(D^2)/4#

D is the diameter

#A=3.14times(4.2^2)/4 = 13.85# #cm^2#

Your answer is #13.85# #cm^2#

Jul 31, 2018

Area of circle #A = 13.86 # #cm^2#

Explanation:

Area of circle #A = pi r^2#

Radius (r) = Diameter (d) / 2

Given #r = d / 2 = 4.2 / 2 = 2.1 cm#

#Area = A = pi r^2 = pi * 2.1^2 = (22/7) * 2.1^2 = 13.86 cm^2#