Radii OA and OB were drawn in a circle with center O so that the angle AOB is equal to 140 degrees.

Radii OA and OB were drawn in a circle with center O so that the angle AOB is equal to 140 degrees. What is the value of the angle AOB?

A circle is a closed plane curve that consists of all points in the plane that are equidistant from the backsight point. This point is called the center of the circle.
If you mark two points on a circle, they divide the circle into two arcs.
Each arc has a degree measure.
The sum of the degree measures of two arcs with common ends is 360 °.
Center angle – the angle with the apex at the center of the circle.
The degree measure of the central angle is equal to the degree measure of the corresponding arc of the circle.
If the sum of the angles AOB and ∠BOA is 360 °, then the degree measure of the angle BOA is:
∠BOA = 360 ° – ∠AOB;
∠BOA = 360 ° – 140 ° = 220 °.