# Geometry help:-(

By hennars

@hennars (250)

United Arab Emirates

February 12, 2007 12:02am CST

This is about Area of circle and circumference prob that I'm not so good at them.Please advice.
We know formula of circle area = pi x r x r (answer must be given square units at the end)
while circle circumference is C=pi x 2 x r
But I'm doubtful how to work out of these below prob( use pi = 3.14)
Also how to make out which formula to work out;-P
1)Given circle with circumference of 31.4m, find its area?
2)Given circle with area of 314m(sq.units ie 2), find its circumference.
Many thanks in advance

1 response

@twinkle76 (103)

• Philippines

12 Feb 07

for question 1 : substitute circum value 31.4m to circumference formula, thus u get the value of r.. then substitute the value of r in the formula of area..that's how simple.. i think you havn't paid much attention to your teacher, this is simple algebra.. you do the same principle to question number 2. hope i helped you..