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Circles are one of the most common shapes that we observe everywhere around us. A ball, a pizza, a pie, a wheel, a plate, a coin, and so on are a few circular objects that we come across in our daily life. A circle is a two-dimensional figure formed by a set of points that are at a constant or at a fixed distance (radius) from a fixed point (centre) on the plane.
Let’s understand how to draw a circle.
How to Draw a Circle Using Compass?
Since the points lying on the boundary (or perimeter), (or circumference) of a circle are equidistant from the centre, a circle is drawn by using an instrument with two ends – one is fixed at a point and the other is stretched out to draw a curve (circle).
Steps For How to Draw a Circle Using Compass
The following steps are used to draw a circle of $3 \text{cm}$.
Step 1: Place the pointer of the compass at the initial point of the ruler ($0 \text{cm}$) and extend the other end of the pencil measuring $3 \text{cm}$ from the initial point (i.e. $3 \text{cm}$).
Step 2: Mark a point $\text{O}$ on a piece of paper. This point is supposed to be the centre of the circle that you are about to construct.
Step 3: Place the pointer of the compass at point $\text{O}$.
Step 4: Turn the compass slowly through $360^{\circ}$ to draw a circle.
Make sure that you hold the point of the compass stiffly on the paper. You are also required to move the compass through the $360^{\circ}$ in one go for accuracy and neatness.
How to Draw a Circle Using Pin?
Let’s now understand an easy method of how to draw a circle without a compass. In this method you need a pin and a rubber band.
The steps followed to draw a circle using a pin and a rubber band are:
Step 1: Place paper on top of a piece of cardboard. Any kind of cardboard will work, as long as it’s thick and a pin can push through it.
Step 2: Push a pin through the paper and the cardboard. Position the pin so it’s in the spot where you want the centre of the circle to be. Make sure it’s secure in the cardboard so it doesn’t shift when you’re drawing the circle.
Step 3: Put a rubber band around the pin. The larger the rubber band, the bigger your circle will be. If you want to draw a small circle, use a small rubber band or wrap the rubber band around the pin twice. If you don’t have a rubber band, you can tie a piece of string into a circle and use that instead.
Step 4: Place the tip of a pencil on the other end of the rubber band. At this point, the rubber band should be wrapped around both the pin and the pencil.
Step 5: Pull the rubber band taut and draw a circle with the pencil. Make sure you keep the rubber band pulled taut while you draw the circle so it’s even.
Key Takeaways
- With a centre and a given radius, only one circle can be drawn.
- Given any three non-collinear points $\text{A}$, $\text{B}$, and $\text{C}$, there exists a unique circle passing through them.
- If $\text{A}$, $\text{B}$, and $\text{C}$ are collinear, then the perpendicular bisectors of $\text{AB}$ and $\text{BC}$ would never intersect (they would be parallel).
Practice Problems
- If you draw a circle of radius $2.5 \text{ cm}$, what will be its diameter?
- If you want to draw a circle of diameter $8 \text{ cm}$, how much will you stretch the compass needle?
- What are the steps to draw a circle using a ruler and a compass?
FAQs
What are the different parts of a circle?
The different parts of a circle are centre of the circle, radius, diameter, circumference, arc, sector, and segment.
What are the tools used to construct a circle?
The tools used to construct a circle are the ruler and compass.
How many circles can be drawn through $3$ non-collinear points?
We can draw only one circle through three non-collinear points.
Conclusion
A circle is a two-dimensional figure formed by a set of points that are at a constant or at a fixed distance (radius) from a fixed point (centre) on the plane. A ruler and a compass are used to draw a circle of the desired radius neatly and precisely.
Recommended Reading
- What is a Circle – Parts, Properties & Examples
- How to Construct a Perpendicular Line (With Steps & Examples)
- How to Construct Parallel Lines(With Steps & Examples)
- How To Construct a Line Segment(With Steps & Examples)
- What are Collinear Points in Geometry – Definition, Properties & Examples
- What is a Transversal Line in Geometry – Definition, Properties & Examples
- What are Parallel Lines in Geometry – Definition, Properties & Examples
- What is Concurrent lines in Geometry – Definition, Conditions & Examples
- What is Half Line in Geometry – Definition, Properties & Examples
- What is a Perpendicular Line in Geometry – Definition, Properties & Examples
- Difference Between Axiom, Postulate and Theorem
- Lines in Geometry(Definition, Types & Examples)
- What Are 2D Shapes – Names, Definitions & Properties
- 3D Shapes – Definition, Properties & Types
