Sebuah lingkaran dg sudut pusat aob=60˚ jika jari-jari lingkarannya 21 cm panjang busur AB adalah
MicoArrafi
![$\begin{align} P_{b[AB]}&=\frac{\angle AOB}{\angle\odot}\times2\times\pi\times r\\&=\frac{60^{\circ}}{360^{\circ}}\times2\times\frac{22}{7}\times21\ cm\\&=\boxed{\boxed{22\ cm}} \end](https://tex.z-dn.net/?f=%24%5Cbegin%7Balign%7D+P_%7Bb%5BAB%5D%7D%26%3D%5Cfrac%7B%5Cangle+AOB%7D%7B%5Cangle%5Codot%7D%5Ctimes2%5Ctimes%5Cpi%5Ctimes+r%5C%5C%26%3D%5Cfrac%7B60%5E%7B%5Ccirc%7D%7D%7B360%5E%7B%5Ccirc%7D%7D%5Ctimes2%5Ctimes%5Cfrac%7B22%7D%7B7%7D%5Ctimes21%5C+cm%5C%5C%26%3D%5Cboxed%7B%5Cboxed%7B22%5C+cm%7D%7D+%5Cend "$\begin{align} P_{b[AB]}&=\frac{\angle AOB}{\angle\odot}\times2\times\pi\times r\\&=\frac{60^{\circ}}{360^{\circ}}\times2\times\frac{22}{7}\times21\ cm\\&=\boxed{\boxed{22\ cm}} \end")
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