Skeletal Geo Set is a great math manipulative for hands-on discovery of 2D and 3D geometry principles. Make your own 2D figures and skeletal 3D models. Learn about vertices, faces and edges while involved in constructing new models. Quarter curve pieces enable students to build and investigate properties of circles and cylinders. Contents include 330 pieces: 60 white balls, sticks of 50 each of 1.29" , 2.08" , 2.72" , 30 each of 3.32" , 4.13" , 4.92" and 30 quarter circles with 20 double-sided activity cards.