Question

In the given figure show that
AB II EF

Answer 1

Angle BCD= angleBCE+angleDCE

=25+35=60

Angle ABC =angleBCD

But these are alternate angles

ThereforeAB||CD————1

Now,

Angle FEC +angleDCE=145+35=180

The adjacent angles are supplementary.

Therefore, CD||EF————-2

Using 1 and 2

AB||EF