Question

Answer for the third question please I need the answer very fast

Answer 1

the AOB angle is 86 degree.

Answer 2

draw an imaginary line CO
so <OAC = <OCA = <20 {isosceles triangle have same base angles}
    using same logic < OBC = < OCB = <18

SO , <ACB = <OCA + <OCB
                     = 20+18

<ACB = 38

<AOB is twice <ACB {angle at centre is twice angle at circumference}

so < AOB = 2*<ACB
                  = 2*38
                  = 76

SO <AOB = 76

hope it helped you !!!