To draw longitude lines on a 2D globe, it's essential to understand that they will appear as half-ellipses due to the projection method used. The Mercator projection is a common choice for this purpose, but other projections may also be considered depending on the desired visual representation. Techniques for drawing ellipses are crucial for accurately depicting these lines. Exploring various projection methods can enhance the overall design of the globe. Understanding these concepts will aid in creating a more accurate 2D representation of a sphere.