As given, the diagram contains insufficient information to determine the angle a because the orientation of line segment EG can be varied independently of that of line segment FH.
Still, it appears that the line segments EG and FH are reflections of one another through a line that is perpendicular to the parallel pair of line segments AB and CD. If this assumption is correct, then:—
• By symmetry, the angle of intersection between EG and CD is also 70°;
• By parallel translation, the angle of intersection between EG and AB is also 70°; and
• Therefore, a = 180° – 70° = 110°.
'Luthon64
"Sensitive" people are now carefully examining the entire universe, trying to find something to be "offended" at. It won't stop until such time as the "offenders" learn to stop apologizing, and saying "freck off" instead. — brianvds, The ShoutBox Classics, 02/07/2018.