What is the supplement of an abgle that mesure 80 degrees

100 because supplementary angles equal 180°
hope this helps

Supplementary angle = the sum of two angles that equal 180 degrees.

x + 80 = 180

Where x is the supplementary angle. Using some basic algebra, transpose the 80 to the right side and simplify.

x + 80 = 180
x         = 180 - 80
x         = 100

So, the supplementary angle is 100 degrees.

The answer is b: step 2.