Nodes and antinodes always alternate, they’re equally spaced, and the distance
between two successive nodes (or antinodes) is equal to λ. This information can
be used to determine how standing waves can be generated. The following figures
show the three simplest standing waves that our string can support. The first
standing wave has one antinode, the second has two, and the third has three. The
length of the string in all three diagrams is L.