Question

In figure, O is the centre of circle, angle CAO=30 and angle CBO=40 . find angle AOB.​

Answer 1

Answer:

i am not very sure about my answer, but i believe

AOB = 140°

because in acb should be a sum of 40 and 30

i.e 70° (this is a rule)

the angle in the centre is always double of the angle on the circumference (provided both are suspended from same two points on the circumference)

so, 70×2 =140°