Answer:
Θ = 39°
Step-by-step explanation:
OA = OB ( radii of the circle ) , then
Δ AOB is isosceles with base angles congruent , that is
∠ ABO = ∠ BAO = 52°
the exterior angle of a triangle is equal to the 2 opposite interior angles.
∠ DOB is an exterior angle of the triangle , so
∠ DOB = ∠ ABO + ∠ BAO = 52° + 52° = 114°
the angle between a tangent and the radius at the point of contact is 90°, then
∠ OBC = ∠ ODE = 90°
the sum of the 4 interior angles of quadrilateral OBCD = 360°
∠ OBC + ∠ DOB + ∠ ODC + ∠ BCD = 360°
90° + 114° + (90 + 27)° + Θ = 360°
90° + 114° + 117° + Θ = 360°
321° + Θ = 360° ( subtract 321° from both sides )
Θ = 39°
