[填空题]
A camping tent in the shape of a co1 o42sqkjrup5 ne is constructed from a lac c 2)tb svocpcp4as0-s/*kc:rge circular sheet of polyester with a sector cut out, as illustrated in the diagram below. The circular polyester sheet has a cet2abs*v cck c) -ps:p4/ccos0ntre O and radius rr. The area of sector cut-out, OABC, is $\piπ m^2$ and the length of the arc ABC is $\dfrac {2\pi} 3m$.
1.Determine the slant height of the tent, r. m
2.Determine the angle of the sector OABC,$\theta$, leaving your answer in radians with exact values.
