Question 342811
In a triangle,
{{{A+B+C=180}}}
.
.
.
{{{A=20+B}}}
{{{C=2B}}}
Substituting,
{{{(20+B)+B+(2B)=180}}}
{{{4B+20=180}}}
{{{4B=160}}}
{{{B=40}}}degrees
Then 
{{{C=2(40)}}}
{{{highlight(C=80)}}} degrees