side, sighed

Side or side means one of the surfaces of a building, box, or some other object--
 Look on the other side of the house.
The hypotenuse is the long side of the triangle.
Side may mean one of the surfaces of a flat object, such as a sheet of paper--
Now turn the paper over and write on the other side.
Side or side may mean one of the halves of something, literally or figuratively--
He has a pain in his side.
He has a pain in his left side.
Is he on the conservative side or the liberal side?
Which side are you on?

Sighed or sighed ( rhymes with side ) is the past tense ( yesterday, or some time ago ) of "sigh", meaning to let out a breath audibly, as in resignation or sorrow--
She sighed when she heard the news, but then went on with what she was doing.
He sighed in resignation, then set out to finish the job.

Now that you know that, you can say--
"He sighed as he thought about painting the other side of the fence."