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# Compass (Drawing)|Definition & Meaning

## Definition

A compass is a drawing instrument used in geometry to draw circles, and arcs and measure distances.

**Design of Compass**

Compasses typically have two legs that connect at a joint and are constructed of **metal**. The circle’s or arc’s size can be adjusted by moving legs apart depending upon the measurements. The ends of one component are sharp, pointed spikes, and the other is a pencil. Design of a compass is illustrated in figure 1

Compasses come in two varieties that are **mechanical** and **conventional**. A mechanical compass has a mechanical pencil and a conventional or normal compass has a normal pencil.It is simple to locate the compass that is most suited for the circle you wish to create because there are many **different compasses**, both large and little, accessible for selection.

When drawing a stroke, align the legs** perpendicular** to the paper if one or both of them have joints. Make a full stroke with the compass in a single motion without pausing or going backward to optimize stroke quality. The compass may be used with an extension bar to draw circles with up to a 25 cm diameter.

When using the compass needle to draw many circles with the same **center,** it’s possible to make a sizable hole in the paper. A center disc can be quite helpful in these** circumstances**. A center disc keeps your circles’ centers true and shields the paper from tearing. A circle template is an additional tool for** drawing circles.**

The user turns the compass to create circles and arcs by using the leg with the needle as an axis. Compass writing implements include **mechanical pencils, pencil lead, and sketching pens**. Certain compasses are made to let the user switch between writing tools.

**Uses of Compass**

A compass is used for drawing **circles**, **arcs** and measuring **distances** on maps. You may draw circles by placing the pencil on the paper, pushing the pencil’s spiked leg into the paper, and then tracing a circle with the pencil. To achieve this, you must avoid moving the legs in any **direction** while you are drawing the circle.

By adjusting the distance between the legs, a circle may be made larger or smaller. Distance between the legs depends upon the** radius of a circle**.

**Dividers and compasses** with two spikes can be used to measure distances on a map. The distance between the spikes on the map represents a **real-world distance**. The distance between two points on a map may be determined by counting how many times the compasses fit between them.

Drawings with a compass and straightedge are used to illustrate concepts in planar geometry. On paper, actual compasses are utilized, but the ideal compass employed in proofs is a fictitious, ideal device that creates ideal circles.

The **“collapsing compass”** is the most exact characterization of this perfect explanation instrument. It can only be used once and creates a circle with the provided **radius from the supplied location**. That is to say, it cannot simply be transferred to another location and utilized to create another identical circle like a real pair of compasses.

**Angles** can also be constructed using compasses and rulers. After drawing a line segment AB takes O as a center point to draw and an arc then using the end of the arc as a center point we make the first cut on the arc which represents the** 60-degree** angle.

Then using** 60-degree angle** as the center make another cut on the arc which shows the **45-degree angle** the using both the cut of **60 and 45** we make two cuts which show the** angle of 90 degrees.** We can also plot the angle of 135 by taking 45 degrees and the other end of the arc as the center as shown in figure 1.

**Different Variants of Compasses**

**A beam compass** is a tool used for drawing and dividing circles that are bigger than those produced by a typical pair of compasses**. Scribe compasses** are the simplest form of the compass. The metal branches on both are crimped. While one branch has a pencil sleeve, the other is crimped and has a point sticking out at the end**.**

** Loose-leg wing dividers** are used to step off repeating measurements and draw circles with some precision. The brass pivot, thumb screws, pencil holder, and branches are all well-constructed.

**A proportionate compass** also referred to as a military compass or sector—was a tool used for calculating. It is made up of two equal-length rulers connected by a hinge. On the rulers are many scales that can be used for mathematical calculations. To decrease or increase patterns while maintaining angles, a **reduction compass** is utilized.

**Drawing Different Geometries With a Compass**

**Example 1**

Draw a circle having a radius of 2 cm with a compass.

**Solution**

Open the legs of the compass of 2 cm and put the pointed spike at a point i.e. A and then draw the circle as illustrated in figure 2.

**Example 2**

Draw an arc of radius 2 cm with a compass.

**Solution**

Open the legs of the compass of 2cm and put the pointed spike at a point i.e. A and then draw an arc between B and C as illustrated in figure 3.

**Example 3**

Draw an angle of 90 degrees with a compass.

**Solution**

Draw a line segment OA. Draw an arc cutting the line segment OA at point B with a small radius. Using the same radius, fix the compass at B and arc cutting the first arc at C. Again, keeping the same radius, fix the compass at C and draw an another arc cutting the first arc at D. Draw two arcs using C and D to join at E. Then pass a line segment through O and point E as illustrated in figure 4.

*All images/mathematical drawings were created with GeoGebra.*