Question

solve step by step instructions ......

Answer 1

Answer:

very easy

Step-by-step explanation:

∠a = 70

∠b=40

∠c= ?

∠a+∠b+∠c = 180                   {angle sum property of triangle}

70+40+c=180

110+c=180

c=180-110

c=70

BCD is a straight line

∠c=70

so ∠c+∠ACD =180                {straight line}

70+∠ACD = 180

∠ACD=180-70

⇒∠ACD = 110

OR a simple way is

∠a +∠b = ∠ACD

70+40=∠ACD

⇒∠ACD = 110