The triangles formed are iscocleles triangles making their bases the same angle measures. Additionally, RST anf RGT are congruent since they are each equal to 1/2 of RQTS
We also know that the interior angles of any triangle add up to 180°
Therefore,
m<R + m<T + 126 = 180
m<R + m<T = 54
Since m<R and m<T are equal, R and T must be equal to 27
