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      Geometry Problem 480: Triangle, Circle, Center, Altitude, Angle, Circumcenter. |  
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              The figure shows a triangle ABC with 
				circumcenter O and altitude BD. Prove that angles OBA and CBD 
				are congruent.
Circumcenter of a triangle is the center of the 
				circle which passes through the vertices. 
 
 
 
				
				 
 
 
				  												
						
  						  
      Problem 480 on Twitter
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