This problem involves a circle with center O and a triangle AOB where OA and OB are radii. We are given that angle OBA = 76 degrees.
Since OA and OB are radii of the same circle, triangle AOB is an isosceles triangle with OA = OB.
In an isosceles triangle, the angles opposite the equal sides are equal. Therefore, angle OAB = angle OBA.
So, angle OAB = 76 degrees.
The sum of angles in a triangle is 180 degrees. In triangle AOB, the sum of angles is angle OAB + angle OBA + angle AOB = 180 degrees.
76 degrees + 76 degrees + angle AOB = 180 degrees
152 degrees + angle AOB = 180 degrees
angle AOB = 180 degrees - 152 degrees
angle AOB = 28 degrees.
Ответ: 28°