90. Iron rods a, b, c, d, e and f are making a design in a bridge as shown in Fig. 5.47, in which a ∥ b, c ∥ d, e ∥ f. Find the marked angles between
(i) b and c
(ii) d and e
(iii) d and f
(iv) c and f
(i) 30°
(ii) 105°
(iii) 75°
(iv) 75°
Using parallel lines and transversal properties, corresponding and alternate interior angles are calculated as shown.