Petra Phoenix Geometry Box Full Set (SKU - BD - 1025190963)

Summary:

Perfect professional drawing or drafting stationery tool And Cheap Price. Great gift for students back to school from the holiday. Geometry box is a mathematical drawing instrument. Look inside for timetable And Formula Sheet.
Basic Tools: Straightedge: A straightedge is a geometric tool used to construct straight lines. It contains no marks. As the name says, it is a ""straight edge."" A ruler can be used as a straight edge by simply ignoring the measuring marks on it.

Ruler: A ruler is a geometric tool used to measure the length of a line segment. A ruler is basically a straight edge with marks usually used for measuring either inches or centimeters. To use a ruler, place the zero mark on the point to begin the measurement. To stop measuring, look at the mark on the ruler that lies over the point at which the measurement is to end.

Compass: A compass is a V-shaped tool used to construct circles or arcs of circles. (See sketch below on left.) One side of the ""V"" holds a pencil, and the other side is a point. The point anchors the compass at one location on the paper as the tool is turned so the pencil can trace circles, arcs, and angles. A compass is adjustable: the setting determines how far away from the point the arc would be located. Once the user determines the correct setting, the compass is turned around its anchoring point so that the pencil creates a mark, an arc, or a full circle.

Protractor: A protractor is a geometric tool in the shape of a semicircular disk, as shown above on the right. It is used to measure the size of an angle in degrees—usually from 0 to 180 degrees. To use a protractor, lay the protractor on the angle to be measured. There will be a mark on the bottom of the protractor (the straight edge of it) indicating its middle. Place this mark over the origin of the angle, and align the straight edge of the protractor with one side of the angle. Where the other side of the angle intersects the protractor, there will be a mark with a number next to it. This measurement is the measure of the angle.