The line perpendicular to a line with a slope of 1/5 has a slope of -5.
The slope of a line is undefined if the line is vertical.
The slope of a line perpendicular to one with slope m is -1/m. So for a line with slope 1/7, any line perpendicular to it will have: slope = -1 / (1/7) = -7
A vertical line has a slope of infinity.
Well since the lines are parallel they would have the same slope. And the slope of any horizontal line is 0. The slope of a vertical line is undefined.
IND Crosstown Line was created in 1933.
IND Culver Line was created in 1919.
IND Rockaway Line was created in 1956.
IND Concourse Line was created in 1933.
IND Fulton Street Line was created in 1936.
IND Queens Boulevard Line was created in 1933.
Avenue I - IND Culver Line - was created in 1919.
IND Eighth Avenue Line was created in 1932.
Classon Avenue - IND Crosstown Line - was created in 1937.
Greenpoint Avenue - IND Crosstown Line - was created in 1933.
Avenue P - IND Culver Line - was created in 1919.
Avenue N - IND Culver Line - was created in 1919.