This online dictionary of art terms from Artlex is a valuable tool. Line is on the Li page. Just scroll down to Line and read a definition with links or look at a sample works of art by Rembrandt or Richard Long. There are quotes by...

A collection of highly engaging learning modules on various topics within mapping skills. Covers map symbols, how to use four- and six-figure grid references, cardinal directions, distance, contour mapping, and drawing cross-sections....

Learn about one of the basic elements in music, melody. Discover the ideas of melodic shapes and phrases as well as motifs and themes, and how to present these topics to children.

Easy-to-understand information and a colorful diagram on the underground and surface mining methods used for extracting coal.

In this lesson, middle schoolers learn how to determine location by triangulation. We describe the process of triangulation and practice finding your location on a worksheet, in the classroom, and outdoors.

One of the elements of music is "Texture." This site gives the definition, which basically is the relationship between melodic and harmonic.