Q5 of 115 Page 8

In Fig 8.109, if AB ||CD and CD||EF, find ∠ACE.

Since,

EF ‖ CD

Therefore,

∠EFC + ∠LEC = 180^o(Co. interior angles)

∠ECD = 180^o – 130^o

= 50^o

Also, BA ‖ CD

∠BAC = ∠ACD = 70^o(Alternate angles)

But, ∠ACE + ∠ECD = 70^o

∠ACE = 70^o -50^o

=20^o

In Fig 8.107, AB ||CD ||EF and GH ||KL. Find ∠HKL.

In Fig 8.108, show that AB|| EF.

In Fig 8.110, PQ||AB and PR||BC. If ∠QPR = 102°, determine ∠ABC. Give reasons.

In Fig 8.111, state which lines are parallel and why?