Answer:
<S = <I means that the triangle IRS is an isoceles.
The midpoint (T) cutting both congruent side length sides at the same angle means that Line TG and Line TA are equal.
T being the midpoint means Line TI = Line TS.
Given that angles <G and <A are same.
You can use SSA (side-side-angle) to prove triangles are congruent so line SG is equal to Line IA.
Step-by-step explanation: Triangle ITA