Question

In the given figure, line l is parallel to BC. find the values of a, b and c. Write proper reasons.

Answer 1

Answer:

In triangle ABC , by angle sum property :

angle ABC + BCA + CAB = 180°

45°+55°+ b = 180°

b = 180-45-55

b = 180- 100

b = 80°

angle a is alternate angle to angle ABC

angle c is alternate angle to angle ACB

and alternate angles are equal , thus

angle ABC = a = 45°

angle ACB = c = 55°