in the given figure TAS is a tangent to a circle with centre O.at the point A, if angle OBA=320. find the value of x?
in the given figure TAS is a tangent to a circle with centre O.at the point A, if angle OBA=320. find the value of x?
As the figure is not very clear, if TAS is the tangent to the circle at point A , and A, B and C are the points on the circumference .
so the solution is:
∠OAB=90 deg. [line joining the point of contact to the centre is perpendicular to the tangent]
∠BAS=90-∠OAB=90-x
∠ACB=∠BAS [The angle between a tangent and a chord through the point of contact is equal to an angle in the alternate segment.]
∠ACB=90-x
∠AOB=2∠ACB=2(90-x)=180-2x [the angle at the centre is twice the angle at the circumference]
now in triangle AOB,
∠OBA=32 deg, ∠AOB=180-2x , and ∠OAB=x
now since the sum of the interior angles in a triangle is equal to 180 deg.
OR
in the triangle OAB,
OA=OB= radius of the circle
therefore ∠OAB=∠OBA=32 deg.