Question 1096247
Let's call the angle, a. Half of it (a/2) plus its supplement (180-a) is equal to 3 times its complement (90-a).

{{{a/2 + 180-a= 3*(90-a)}}}
{{{a/2 + 180-a= 3*90-3a}}}
{{{a/2+180-a=270-3a}}}
Unknowns on one side, numbers on the other
{{{a/2-a+3a=270-180}}}
{{{a/2+2a=90}}}
Get rid of the denominator
{{{a*2/2+2*2a=90*2}}}
{{{a+4a=180}}}
{{{5a=180}}}
Solve for a
{{{5a/5=180/5}}}
{{{a=36}}}
So its supplement is equal to
{{{180-36=144}}}
and its complement is equal to
{{{90-36=54}}}