Question

On the figure ab is parallel to cd and de is parallel to cf then find the value of x.

Answer 1

∠ABC=180-(60+40).....(angle sum property of triangle)

∠ABC=80°

AB║CD.....(given)

∠ABC=∠DCF.....(corresponding angles on same side of transversal b/w parallel                         lines are equal)

DE║CF

∠DCF+∠CDE=180°.....(internal angles are equal)

80+x=180°

x=100°

hope it helps!