Question 349157
HI,
*Note: the sum of supplementary  angles is 180 degrees
Let x be the angle asked for (the smaller one)
{{{(x + 20)}}} would be the other (it is 20 more than the angle in question)
.
{{{x + (x + 20) = 180}}}
.
simplify and solve for x
{{{2x + 20 = 180}}}
.
{{{2x = 160}}}
x = 80 degrees  ( THE ANGLE ASKED FOR)
.
check Your answer:
(x + 2O) =  100 degrees (then the OTHER)
80degrees  +  100degrees  = 180degrees