Diagram shows sector OAB and ODC with centre O. It is given that OA is 6 cm, the ratio of OA:OD = 2:3. Find the length of OD.

Diagram shows quadrant AOC with centre O. Given that the radius of the quadrant is 9 cm and angle OAB is $57\degree$. Find the angle BOC. (Use: $\pi$=3.142)

Diagram shows quadrant AOC with centre O. Given that the radius of the quadrant is 9 cm and angle OAB is $57\degree$. Find perimeter of sector BOC. (Use: $\pi$=3.142)

Diagram shows a sector POQ with centre O. Given the minor arc length of PQ is 6.5 cm and major angle of POQ is $285\degree$. FInd perimeter major POQ. (Use: $\pi$=3.142)