In Fig. 9.39, AB || DE . Find ∠ ACD .

Question

In Fig. 9.39, AB || DE . Find &#x2220; ACD .

Philoid · Accepted Answer

Since,

AB ‖ DE

∠ABC = ∠CDE (Alternate angles)

∠ABC = 40^o

In

∠A + ∠B + ∠ACB = 180^o

30^o + 40^o + ∠ACB = 180^o

∠ACB = 180^o – 70^o

= 110^o (i)

Now,

∠ACD + ∠ACB = 180^o (Linear pair)

∠ACD + 110^o = 180^o [From (i)]

∠ACD = 180^o – 110^o

= 70^o

Hence, ∠ACD = 70^o.