數學問題(圓周)

面積 = 36丌cm^2
直徑 = 12cm
圓的周界 = 12丌cm

由於面積是半徑x半徑x丌.....so we can know 半徑 is 6cm
由於圓的周界是直徑x丌.......so we can know圓的周界 is12丌cm

面積 = 36丌cm^2
直徑 = 12cm
圓的周界 = 12丌cm

面積=(R^2 x 丌)cm^2
SO ..the radius of this circle is 6cm
周界=(2R x 丌)cm
SO ..the circumference = (6 x 2 x 丌)cm = 12丌cm

HOPE CAN HELP U!

圓面積:丌r ^2
丌r ^2 = 36丌cm^2
6丌 ^2 = 36丌cm^2
r = 6
圓周:2丌r
2丌(6)
=12丌