A multifunctional writing instrument includes a hollow body, wherein the hollow body comprises one or more cavities configured to attach with a plurality of technical drawing tools. A first writing member having a first writing tip is included. The first writing member includes lead and a mechanical pencil system being provided in a first portion of the hollow body, and wherein the first writing tip is axial with respect to the hollow body. A second writing member having a second writing tip is included. The second writing member comprises ink and an ink pen system being provided in a second portion of the hollow body. The first portion of the hollow body is at an opposite end of the second portion of the hollow body. The second writing tip is axial with respect to the hollow body.

A plotter apparatus inscribes a polygon in a circle, and includes a ruler body, a first slider, a second slider, multiple brachiums, and a nib member. The ruler body comprises a knap, and a first ruler groove and a second ruler groove to allow movement of the first slider and the second slider. The brachiums are connected across the ruler body via pivots. The nib member allows to draw the circle. A fourth brachium is attached to a pre-determined numbered hole on a second and a third brachium as per the number of sides required on the polygon. The length of each side of the polygon is retrieved between the knap and a slider. Cyclic arcs, with the determined length as a length of one side of the polygon, are drawn along the circumference of the circle. The arc intersections on the circle are joined together to define the polygon.

An educational ruler is a protractor, where the protractor can draw and measure angles. The educational ruler includes a planar disk having a semicircular circumference and labeled in scales along the semicircular circumference; a straight line edge connecting two edges of the semicircular circumference; a through hole on the planar disk; a first edge and a second edge extending from the through hole to the straight line edge; a third edge and a fourth edge extending from the semicircular circumference to the straight line edge. The first edge of the through hole of the educational ruler and the second edge of the through hole of the educational ruler intersect at 90 degrees scale of the planar disk to form the first right angle, and the included angle of the first edge of the through hole of the educational ruler and the straight line edge of the educational ruler is 45 degrees.

The present invention provides an installation device comprising a substantially planar first element having a first elongate body having a first end and a second end opposing the first end, the elongate body defining a first longitudinal axis and having a width w1 extending transverse to the first longitudinal axis, the elongate body defining a linear alignment indicator located at a midpoint of width w1 and extending along the length of the first element; and a substantially planar second element having a second elongate body having a first end and a second end opposing the first end, the elongate body defining a second longitudinal axis and having a width w2 extending transverse to the second longitudinal axis, the elongate body defining an engagement channel extending along a portion of the length of the second element, the second elongate body further comprising a plurality of position indicators along at least a portion of its length; and engagement means extending from the first element through the engagement channel and operable to secure the first and second elements to one another, wherein the installation device is moveable between a first configuration in which the first and second elements are pivotable relative to one another about the engagement means; a second configuration where the second element is slidable relative to the first element in a direction parallel to the second longitudinal axes; and a third configuration in which the first and second elements are fixed relative to one another. Also provided is a method of preparation of the aforementioned installation device and a method of use of the aforementioned installation device.

A system comprises at least one layout member configured to be mounted at a site where the layout member includes measurement graduations thereon and is configured to be marked with a marking implement and a template mounted to the layout member and selectively slidable along the layout member to a selected graduation corresponding to at least one coordinate of an installation site for installation of equipment. The template includes one or more apertures. The apertures permit passage of a marking implement to mark the at least one coordinate of the installation site on the layout member.