Question 926774
By definition,
{{{A+C=90}}}
{{{A+S=180}}}
Subtracting,
{{{S+A-C-A=180-90}}}
{{{S-C=90}}}
Also you know,
{{{C/S=1/3}}}
{{{S=3C}}}
Substituting,
{{{3C-C=90}}}
{{{2C=90}}}
{{{C=45}}}
Then,
{{{S=3(45)}}}
{{{S=135}}}