What is Closed Shapes? Definition With Examples

In our day-to-day life, we come in contact with various objects around us. Have you ever thought about their shapes? Why and how does each object have a different shape?

Pick any object near you and closely observe its structure. Start from any one point on the object and see if you can trace its boundary completely and come back to the same point from where you started. This is how we identify closed and open shapes. Let’s look at some examples.

This is a mosquito coil. As you can see, it does not end at the point where it starts, so it is an open shape.

Real life example of open shape

When we draw an open shape, the point where you start will not end at the same point or at the starting point.

Now,  look at the picture of the choco-chip cookie below. Its starting point and ending point are the same, so we can call it a closed shape.

Real life example of closed shape

In a closed shape, the endpoint of the shape meets the point where it began.

What is Closed Shapes?

In geometry, a closed shape can be defined as an enclosed shape or figure whose line segments and/or curves are connected or meet end to end. Closed shapes start and end at the same point. 

The least number of sides required to make a closed shape is 3, which forms a polygon named a triangle.

Difference between Open and Closed Shapes

The following table mentions all the differences between open and closed shapes based on their definitions. Let’s have a look:

Difference between open and closed shapes

Closed Shapes in Geometry

The least number of sides a closed shape can have is 3, which is a polygon named triangle. 

  • A triangle is a three-sided closed shape polygon having three vertices.
A triangle
  • A circle is a closed shape with one face and no sides or vertices. 
A circle
  • A quadrilateral is a four-sided closed shape having four vertices. Square, rectangle, rhombus, parallelogram, and trapezium are some examples of quadrilaterals. 
A Square
  • A pentagon is a five-sided closed shape with five vertices. 
A pentagon

There are many more closed shapes in geometry than the ones listed above! As a matter of fact, a polygon is always a closed shape.

Solved Examples 

Example 1. How many sides does this shape have? Is the shape closed or open? 

An octagon

Solution: First, we count the number of straight lines in the shape.

There are eight straight lines connected to each other, making an octagon. 

As this octagon’s outline may be traced without any gaps, it is a closed shape.

Example 2. Are straight lines necessary to make closed shapes?

Solution: No, straight lines are not necessary to make a closed shape. Some closed shapes that have no straight lines are oval, semicircles, etc. A semicircle is a closed shape with one curved edge and one straight edge.

A semicircle

Example 3. Which of these figures are closed and open shapes?

Open shapes and closed shape

Alt Tag: Open shapes and closed shapeSolution: Option (C) is a circle with no gaps along its boundary. Hence, it is a closed shape. All the other shapes have gaps in their boundaries and hence, they are open shapes.

Practice Problems

What is Closed Shapes? Definition With Examples

Attend this quiz & Test your knowledge

1Which of these is a closed shape?

Shape A
Shape B
Shape C
Shape D
CorrectIncorrect
Correct answer is: Shape C
The circle does not have any gaps along its boundary and hence, it is a closed shape.
What is Closed Shapes? Definition With Examples

2How many sides does this closed shape have?

6
5
8
5
CorrectIncorrect
Correct answer is: 6
This closed shape has 6 sides. It is an irregular hexagon.
What is Closed Shapes? Definition With Examples

3Which of these is a closed shape?

Shape A
Shape B
Shape C
Shape D
CorrectIncorrect
Correct answer is: Shape A
The first shape does not have any gaps, making it a closed shape. It is a square.
What is Closed Shapes? Definition With Examples

4Which of the following is an example of an open shape?

Arc
Circle
Oval
Semi Circle
CorrectIncorrect
Correct answer is: Arc
An arc is an open shape since its endpoints do not meet.

Frequently Asked Questions

In geometry, a closed shape can be defined as an enclosed shape or figure whose line segments and/or curves are connected or meet. They start and end at the same point. Some examples of closed shapes are squares, circles, triangles, stars, kites, trapezium, etc.

Closed shapes made up of 3 or more than 3 line segments are called polygons.

A semicircle has a curved edge and a straight edge that meet end to end. Hence, it is a closed shape.