An angle measures 143.4° more than the measure of a supplementary angle. what is the measure of each angle?

This is a typical story problem that needs to be translated from written words to a workable equation.  "An angle measures" looks like "A =" in equation form.  "...the measure of a supplementary angle" looks like "(180 - A)" and "143.4 more" means you're adding 143.4 to the (180 - A).  So in the end the equation is this: A = (180 - A) + 143.4.  This simplifies to A = 323.4 - A, and adding A to both sides gives us 2A = 323.4 and A = 161.7.  Now check yourself by filling in 161.7 for every A in your original equation and make sure it comes out right and that the right side does in fact equal the left side.  (It does, just check it anyway!)