There are four bases that make up the baseball diamond called first, second, third, and home. The first three bases are all the same size; square shaped pads made of hard rubber or canvas measuring 15 inches on each side and about three to five inches thick. Each base is held into the ground by a metal peg. Home plate is a flat, five-sided piece of rubber that measures 17 inches on the bottom, 8.5 on the sides, and 12 inches on the slants and looks just like a small house, hence the name. They're typically placed 90 feet apart from each other in a diamond shape.