In ΔPQR, we have

Ext. ∠PRT = ∠RPQ + ∠RQP[Exterior angle theorem]

= 35° + 70° = 105°

In ∠PQR; ∠P + ∠PQR + ∠PRQ = 180°

  [Angle sum property theorem]

35° + 70° + ∠PRQ = 180°

∠PRQ = 180° – 105°

∠PRQ = 75°

In ΔPQR, we have

Ext. ∠SQR = ∠P + ∠PRQ     [Exterior angle theorem]

= 35° + 75° = 110°