AB = 6, which is 3/ 16 of the circumference.

∴ perimeter = ab ÷ 3/16 = 6 ÷ 3/16 = 32

∵ABCD is quadrilateral

∴AB=CD

∴BC=32-2*AB=32-6*2= 10

2、

∫AC+BD = 36

∴OC+OD=36÷2= 18

∫AB = 1 1

∴CD= 1 1

∴△OCD perimeter = OC+OD+CD =18+11= 29.