How do you find the area of a circle if the circumference of a circle is 28.26cm?
1 Answer
May 24, 2018
Explanation:
#"the area (A) of a circle is given by"#
#•color(white)(x)A=pir^2larrcolor(blue)"r is the radius"#
#"to calculate A we require to find r"#
#"the circumference (C) of a circle is given by"#
#•color(white)(x)C=2pir#
#"here "C=28.26 " so equating"#
#2pir=28.26#
#"divide both sides by "2pi#
#(cancel(2pi) r)/cancel(2pi)=28.26/(2pi)#
#r=28.26/(2pi)larr" round on final step"#
#"substitute this value into formula for A"#
#A=pixx(28.26/(2pi))^2~~63.55" to 2 dec. places"#