the radius of semi circle is 30 cm.Find its circumference
Note:what formula can i use
(pie*r + 2r) or (pie*r + r)
Don't become obsessed with formulas, just think it through.
you want the distance around 1/2 of a circle
= (1/2)(2π(30)) = 30π
Then you must add the diameter, which would be 60 cm
total = 30π + 60
which looks like πr + 2r