O is the centre of a circle P and Q are the two points on the circumference of the circle such that ?POQ = 800, tangent draw on point P and Q intersect eachother on the point T. Find the ?PTQ.

The angle between two tangents drawn from an external point to a circle equals the angle subtended by the line segment joining the points of tangency at the center, minus the central angle. Since angle POQ is 80°, the angle PTQ = 180° - 80° = 100° (as quadrilateral OPTQ has sum of angles = 360°, and angles at P and Q are each 90° since tangents are perpendicular to radii). 80° would be the central angle itself, not the exterior angle. 60° and 75° are not related to the tangent properties.