Abstract: A construction system includes one or more body members each having one or more apertures extending through a body wall to a cavity forming a socket. Each body member further has one or more balls spaced-apart from the body and attached to the body by an arm. The body wall and/or ball is formed of a flexible and resilient material, and the ball is sized slightly larger than the aperture to connect two body members together by inserting the ball of one member through the aperture of another. The system may include rod members having opposite ends and spherical-shaped balls formed on each end; disk members having an annular groove and open in a radially-facing direction to receive balls; a base member; and/or decorative members.

Abstract: A method and apparatus for teaching a relationship of trigonometric functions between a unit circle and a rectangular coordinate system has a primary flexible member movable between a circular configuration defining the unit circle, and a straight configuration defining the rectangular coordinate system. A plurality of secondary linear members are removably coupled at attachment points along the flexible member. The linear members are movable with the flexible member between a unit circle position and a rectangular coordinate position. In the unit circle position, each linear member is oriented with respect to the unit circle to demonstrate and represent a trigonometric function. In the rectangular coordinate position, each linear member extends perpendicularly from the flexible member defining trigonometric wave forms. The flexible member and linear members physically represent the trigonometric functions and moving the members between the two systems demonstrates the relationship between them.