Complete the proof.
given: ad || bc, ab ||cd
prove: < b = < d

A

B

=

C

D

already given

A

D

=

B

C

already given

and  

A

C

=

A

C

common

Hence  

Δ

A

B

C

≡

Δ

A

C

D

∴

∠

D

A

C

=

∠

B

C

A

- both opposite equal sides  

D

C

and  

A

B

, and

∴

C

D

||

A

B

- as alternate angles are equal

∴

∠

D

C

A

=

∠

C

A

B

- both opposite equal sides  

A

D

and  

B

C

∴

A

D

||

B

C

- as alternate angles are equal

As opposite sides of quadrilateral are parallel,

A

B

C

D

is a parallelogram.

Q

.

E

.

D

.

answer: need picture of problem

step-by-step explanation: