A regular nine side 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 ?	Choices:
A) 48 degrees B) 54 degrees C) 72 degrees D) 70 degrees E) 108 degrees
its a regular nine side so divide the globe by 9.   = 360/9= 
<gadget id="calculator">360/9</gadget>
<output>40</output>
40   40 would be the angle at O.   Angles at A and B are equivalent, so   40 + 2x= 180   2x = 140   x = 70   Angles OAB and OBA will be 70 degrees each.   70 degrees
<result>D</result>
A regular nine side 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 ?