These round engraved acrylic earrings features the formula for figuring out the circumference of a circle (2 pi r). The "r" radius is marked on the earrings. A fun accessory for someone who loves math or geometry!
Ear wires: Sterling silver Sterling silver is more expensive than silver-plated wires, but often works better for those who are sensitive to metals. With cheaper silver-plated wire, only the top coat is silver and this may wear away over time and expose the base metal below. With sterling silver, the entire wire is made with silver, so you don't have to worry about it. Earrings come with rubber ear nuts (backs). Exact type may vary.
Length: Length is measured from the top of the ear wire (the part that will be in your ear) to the bottom of the earring.
