It is called a square. When and how polygons are taught in primary school What is taught How it might be taught Year 1 Children are taught to name common 2D shapes including polygons such as squares, rectangles, triangles, pentagons, hexagons and octagons. Children may learn the shapes through matching activities, going on a shape walk in the school grounds, flash-cards and games. They will look at real-life examples of shapes as well as pictures.
Year 2 Children will be taught to identify properties of shapes such as the number of sides and vertices corners. Children will count the number of sides and corners on the shape. They will describe shapes using the properties, for example: This shape has 3 corners and 3 sides. What is the shape? Year 3 Children will extend their knowledge of polygons to include different types of triangles and quadrilaterals. They will be introduced to heptagons, nonagons and decagons. Knowledge of shape properties will include angles and symmetry of these polygons.
Children will describe shapes and identify them using their properties including symmetry and angles. They might be asked to sort shapes according to their properties using Venn diagrams and Carroll diagrams. Year 4 Children are taught to compare lengths and angles of polygons to decide if they are regular or irregular. Children will be given a range of polygons to sort into regular and irregular; this might be be completing practical tasks or using ICT.
Year 5 Children will be taught to distinguish between regular and irregular polygons based on reasoning about equal sides and angles.
It is expressed in terms of m 2 , cm 2 , ft 2. The perimeter of a polygon is defined as the distance around a polygon which can be obtained by summing up the length of all given sides. It is expressed in terms of units such as meters, cm, feet, etc.
The polygons worksheets will help children recognize more shapes and patterns in real life. It also develops the base of understanding and establishing the necessary basic background for geometry. These math worksheets should be practiced regularly and are free to download in PDF formats.
Download PDF. Example 1: Help Andrea in identifying the shape of polygons out of the given options. Solution: The watermelon slice has one curved side. A polygon should have only straight lines. Thus, the slice of watermelon is not a polygon. The dice is not a polygon because it is three-dimensional. It is a polyhedron. A polygon does not have any open ends. Therefore, the open-ended shape is not a polygon. Hence, the polygons are:.
Example 2: James is very eager to find the interior angle of a regular hexagonal-shaped signboard "STOP". Help James in finding out its interior angle. Solution: Given, the signboard is a regular polygon. The number of sides in a signboard is 6. The plane closed shapes that comprise three or more line segments are referred to as polygons. The world polygon as the name suggests is made of two words "poly" and "gon" where the word poly means "many" and the gon means "angles".
Polygons are always two-dimensional in shape. A polygon whose length of all sides is equal with equal angles at each vertex is called a regular polygon, while an irregular polygon is a polygon whose sides are not equal and angles differ from each other.
These are the parameters that help us in differentiating between a regular and an irregular polygon. The angle that is formed by adjacent sides inside the polygon is referred to as the interior angle.
The values of all the interior angles in a regular polygon are equal to each other. No, a circle is not considered a polygon because it is not made up of three or more straight lines or line segments. It does not fulfill the criterion which can be used to identify a polygon, as it neither has three or more sides nor it shows any angles. Thus, we say the circle is not a polygon. An 11 sided polygon is referred to as Hendecagon. It is derived from two Greek words "Hendeka" which means eleven and "gon" which means angles.
Isosceles Trapezium or trapezoid : Two sides are parallel and base angles are equal, meaning that non-parallel sides are also equal in length. Kite : Two pairs of adjacent sides are of equal length; the shape has an axis of symmetry. Irregular Quadrilateral : a four-sided shape where no sides are equal in length and no internal angles are the same.
A six-sided shape is a hexagon, a seven-sided shape a heptagon, while an octagon has eight sides…. The names of polygons are derived from the prefixes of ancient Greek numbers.
The Greek numerical prefix occurs in many names of everyday objects and concepts. These can sometimes be useful in helping you remember how many sides a polygon has. For example:. There are names for many different types of polygons, and usually the number of sides is more important than the name of the shape. A regular polygon has equal length sides with equal angles between each side. Any other polygon is an irregular polygon , which by definition has unequal length sides and unequal angles between sides.
Circles and shapes that include curves are not polygons - a polygon, by definition, is made up of straight lines. See our pages on circles and curved shapes for more. The angles between the sides of shapes are important when defining and working with polygons.
See our page on Angles for more about how to measure angles. There is a useful formula for finding out the total or sum of internal angles for any polygon, that is:. Furthermore, if the shape is a regular polygon all angles and length of sides are equal then you can simply divide the sum of the internal angles by the number of sides to find each internal angle.
As well as the number of sides and the angles between sides, the length of each side of shapes is also important. If your shape is a regular polygon such as a square in the example above then it is only necessary to measure one side as, by definition, the other sides of a regular polygon are the same length. It is common to use tick marks to show that all sides are an equal length. In the example of the rectangle we needed to measure two sides - the two unmeasured sides are equal to the two measured sides.
It is common for some dimensions not to be shown for more complex shapes. In such cases missing dimensions can be calculated.
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