Q22 of 153 Page 148

In the given figure, AB || CD. If ∠BAO = 60° and ∠OCD = 110°, then ∠AOC = ?

According to question,

AB || CD

AB || DF (DC is produced to F)

OCD=110^o

FCD = 180 – 110 = 70^o(linear pair)

Now in triangle FOC, we have

FOC + CFO + OCF = 180^o

FOC + 60 + 70 = 180^o

FOC = 180 – 130

=50^o

So, AOC = 50^o

In the given figure AB || CD and O is a point joined with B and D, as shown in the figure such that ∠ABO = 35 and ∠CDO = 40°. Reflex ∠BOD = ?

In the given figure, AB || CD. If ∠ABO = 130° and ∠OCD = 110°, then ∠BOC = ?

In the given figure, AB || CD. If ∠AOC = 30° and ∠OAB = 100°, then ∠OCD = ?

In the given figure, AB || CD. If ∠CAB = 80° and ∠EFC = 25°, then ∠CEF = ?