By showing given parallelogram RING,
∵∠R = 70° (given that)
∴∠N = 70°
∵∠N, ∠R are opposite angles
we know that the sum of any two adjacent angles of a parallelogram is 180°, therefore ∠I = 180° – 70° = 110°
so we can write ∠G = 110°
∵ ∠I, ∠G are opposite angles.