3.4.5 Tangents and normals

Problem: Find the angle between the straight line \( (A B) \) and the plane \( (C D E) \), where \( A(1 ; \Gamma ; 2), B(-1 ; H ; 1) \), \( C(\Gamma ; 0 ; 4), D(2 ; \mathrm{H} ; 1), E(\mathrm{H} ; \Gamma ; 3) \), where \( \Gamma=\mathrm{H}=2 \). First write the equations of the straight line and the plane.