[填空题]
A camping tent in th a*xm5 lbld7 xx q,vm659k5uzie shapextj8sv 3(u7c gz -dh8o of a cone is constructed from a large circular sheet of polyester with a sector cut out, as illustrated in the diagram below. The circular polyester sheet has a centre O and radius rr. The area of sector (vgs-oj c38 z x8h7dtucut-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.
