A regular octagon is inscribed in a circle. If A and B are adjacent vertices of the pentagon and O is the center of the circle, what is the value of ∠OAB ?
Choose the correct choice from the following options: A) 48 degrees B) 54 degrees C) 67.5 degrees D) 84 degrees E) 108 degrees
its a regular pentagon so divide the globe by 8.   = 360/8= 
<gadget id="calculator">360/8</gadget>
<output>45</output>
45   45 would be the angle at O.   Angles at A and B are equivalent, so   45 + 2x= 180   2x = 135   x = 67.5   Angles OAB and OBA will be 67.5 degrees each.   67.5 degrees
<result>C</result>
A regular octagon is inscribed in a circle. If A and B are adjacent vertices of the pentagon and O is the center of the circle, what is the value of ∠OAB ?