1) Considering that the sum of the interior angles of a triangle is 180º, i.e., what the triangle angle-sum theorem means
2) Let' solve for y
y+27°+4y+113=180 Combine like terms
5y +140 = 180 Subtract 140º from both sides.
5y = 40 Divide both sides by 5
y=8
2) Hence y = 8
