Information: - Woodworking is the activity or skill of making items from wood, and includes cabinet making (Cabinetry and Furniture), wood carving, joinery, carpentry, and woodturning. - A try square is a woodworking or a metalworking tool used for marking and measuring a piece of wood. The "square" refers to the tool's primary use of measuring the accuracy of a right angle (90 degrees); to "try" a surface is to check its straightness or correspondence to an adjoining surface. A piece of wood that is rectangular, flat, and has all edges (faces, sides, and ends) 90 degrees is called four square. A board is often milled four square in preparation for using it in building furniture. - A tool is any physical item that can be used to achieve a goal, especially if the item is not consumed in the process. Tool use by humans dates back millions of years, and other animals are also known to employ simple tools. - A machinist square or engineer 's square is the metalworkers ' equivalent of a try square . It consists of a steel blade inserted and either welded or pinned into a heavier body at an angle of 90 . In the accompanying image , there is evidence of pinning at the intersection of the blade and body : the heads of three pins are visible as dark circles . A small notch has been added to the inside corner of the square to prevent small particles from accumulating and affecting the square 's reading , by causing it to rock . This notch is typical of machinist squares . - In geometry and trigonometry, a right angle is an angle that bisects the angle formed by two adjacent parts of a straight line. More precisely, if a ray is placed so that its endpoint is on a line and the adjacent angles are equal, then they are right angles. As a rotation, a right angle corresponds to a quarter turn (that is, a quarter of a full circle). - Metalworking is the process of working with metals to create individual parts, assemblies, or large-scale structures. The term covers a wide range of work from large ships and bridges to precise engine parts and delicate jewelry. It therefore includes a correspondingly wide range of skills, processes, and tools. - Wood is a porous and fibrous structural tissue found in the stems and roots of trees, and other woody plants. It is an organic material, a natural composite of cellulose fibers which are strong in tension embedded in a matrix of lignin which resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or it is defined more broadly to include the same type of tissue elsewhere such as in the roots of trees or shrubs. In a living tree it performs a support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients between the leaves, other growing tissues, and the roots. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, or wood chips or fiber. Given the information, choose the subject and object entities that have the relation of 'instance of'.
The answer to this question is:
machinist square , tool