The line equations are Park street: , Main street: , Second street: and Sea street: .

Rewrite the equation of Park street: in the slope - intercept form by solving for y.

Add 2x to each side.

Divide each side by 3.

.

Therefore slope of Park street is .

The equation of Main street: is already adjusted in the slope - intercept form of equation or where m is slope and b is y - intercept.

Therefore slope of Main street is .

Rewrite the equation of Second street: in the slope - intercept form by solving for y.

Divide each side by 3.

.

Therefore slope of Second street is .

Rewrite the equation of Sea street: in the slope - intercept form by solving for y.

Divide each side by 2.

.

Therefore slope of Sea street is .

Therefore slopes of Park street, Main street, Second street and Sea street are , , and respectively.

The slope of Park street and Second street are same, so these streets are parallel.

The slope of Park street, Second street and Sea street are negative reciprocals, so Sea street is perpendicular to the Park street and Second street.

The Park street and Second street are parallel and Sea street is perpendicular to the Park street and Second street.