Question

Use symbols to name all parallel lines.

Answer 1

First let's look at lines GH and JI. They both intersect line AB at a 90° angle. Therefore:

`GH\parallel JI`

Now let's look at lines GJ and HI. They both intersect line CD at a 90° angle. Therefore:

`GJ\parallel HI`

Since GH is not parallel to HI we can discard the 3rd and 4th options. Since the relation expressed in the 2nd option is perpendicularity, we can discard that one as well.

In sumary, we are left with only one option, which also confirms what we obtained previously:

`GH\parallel IJ,\text{ HI}\parallel GJ`