Posted by leena : aww maths !!! help me on .
find the circumference of a circle whose radius is:
1. 8 inches
2. 4 inches

maths 
Writeacher,
http://www.khanacademy.org/math/geometry/basicgeometry/circum_area_circles/v/circlesradiusdiameterandcircumference
Watch this teaching video. Take notes; replay if needed; work it out.
Then let the math tutors know the answers you come up with. Someone will then be able to check your work for you.