Question

in the given figure , what is the value of x will make EF ll CD, if AD ll CD?​

Answer 1

Answer:

Solution:

To be CD∥EF and AB∥CD

∠ABC=∠BCD=65

∘

(By alternate interior angles)

∠BCE+∠ECD=65

∘

or, 30

∘

+∠ECD=65

∘

or, ∠ECD=65

∘

−30

∘

=35

∘

or, ∠ECD+∠FEC=180

∘

(Sum of consecutive interior angles is equal to 180

∘

)

or, 35

∘

+x=180

∘

or, x=145

∘

Hence, B is the correct option.