<PRE><B>Question 343987</B>
NEED TO KNOW:
THE SUM OF THE ANGLES FOR A TRIANGLE IS 180.
{{{A[1]+A[2]+A[3]=180}}}
QUESTION STATES THE FOLLOWING TO BE TRUE:
{{{A[1]=3*A[2]}}} AND {{{A[3]=A[2]+2O}}}
SUBSTITUTE:
{{{(3*A[2])+A[2]+(A[2]+2O)=180
SIMPLIFY
{{{5*A[2]+2O=180}}}
SUBTRACT 20 FROM BOTH SIDES OF THE EQUATION
{{{5*A[2]=160}}}
DIVIDE BOTH SIDES OF THE EQUATION BY 5
{{{A[2]=32}}}
{{{A[1]=96}}} AND {{{A[3]=52}}} ACCORDINGLY

CHECK YOUR ANSWER
96 + 32 + 52 = 180</PRE>