Find the value of x for which d ||m.

A and B are alternate interior angles[tex].[/tex]
∴ ∠A = ∠B
➠ (2x - 20)° = 90°
➠ 2x = 90° + 20°
➠ 2x = 110°
➠ x = 110°/2
➠ x = 55°