Given ray OC is perpendicular to ray OA and <DOA=135 degrees,what would be the measure of <DOC given that <COB=3x-7 and <BOA= -2x+4.

<COA = 90o: Given.

<DOA = 135o: Given.

<DOC = <DOA - <COA = 135 - 90 = 45o.