# 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"#