You can put this solution on YOUR website! Let the angle be A, so its supplement is (180-A), then:
(180-A) = 2A+3 Simplify and solve for A. Add A to both sides.
180 = 3A+3 Subtract 3 from both sides.
177 = 3A Divide both sides by 3.
59 = A
The measure of the angle is 59 degrees.