Which lines of latitude and longitude intersect in illinois?

40 degrees North, 88 degrees West respectivelly

latitudes are the imaginary lines that cuts the earth East to west parralel to the Equator which is the central latitude line. longutudes on the other side cuts the earth from Noth to south parralel to the Greenwhich Meridian. Latitudes have an effect on climate while longitude have an effect of timezones.