Question 357983
By definition,
{{{A+S=180}}}
{{{A+C=90}}}
Subtracting,
{{{A+S-(A+C)=180-90}}}
{{{S-C=90}}}

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{{{S=10C}}}
Substituting,
{{{10C-C=90}}}
{{{9C=90}}}
{{{highlight( C=10)}}}degrees
Then from above,
{{{S=10(10)}}}
{{{highlight(S=100)}}}degrees
{{{A+100=180}}}
{{{highlight(A=80)}}}degrees