Question

A,B and C are the 3 points on the circle and O is the centre of the circle.If <OAB is 40°, <ABC is 120°,<BCO is y° and <COA is x°. Find the value of x° and y°?

Answer 1

y=80°˛ x=120°!

Explanation:

`OA=OB=OC=r`
`∠ OAB=∠ ABO=40°`
`∠OBC=120°-40°=80°`
`y°=∠ BCO=∠ OBC=80°`
`∠COB=180°-2 \cdot 80°=20°`
`∠BOA=180°-2 \cdot 40°=100°`
`x°=∠COB+∠BOA=120°`