Question 342971

1.{{{A+C=90}}}
2.{{{A+S=180}}}
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{{{(1/2)S=2C-12}}}
Multiply both sides by 2.
3.{{{S=4C-48}}}
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Subtract eq. 1 from eq. 2,
{{{A+S-A-C=180-90}}}
{{{S-C=90}}}
Substitute eq. 3,
{{{(4C-48)-C=90}}}
{{{3C-48=90}}}
{{{3C=138}}}
{{{C=46}}} degrees
Then,
{{{S-46=90}}}
{{{highlight(S=136)}}} degrees