2-D Shapes

• In geometry, 2d shapes and 3d shapes are explained widely to make you understand the different types of objects you come across in real life.
• These shapes have their own pattern and properties. Depending on many factors, such as angle, sides, length, height, width, area, volume, etc., the shapes can vary.

2D Shapes Definition

• In maths, 2d shapes can be defined as the plane figures that can be drawn on a flat (or plane) surface or a piece of paper. 
• All the 2d shapes have various parameters such as area and perimeter. Some of the 2d shapes contain sides and corners, whereas some have curved boundaries.

Geometric shapes 

Geometric shapes are regular shapes. Most geometric shapes have straight lines, angles and points. The two exceptions to this rule are circles and semi-circles. 

The ten basic geometric 2D shapes are:

• Circle
• Triangle 
• Semi-circle 
• Square
• Rectangle
• Parallelogram
• Rhombus
• Trapezium 
• Kite
• Polygon

2-D shape names and facts

Circle  

• A circle is a two-dimensional geometric shape.
• A circle has one curved side.
• A circle has no vertices. 
• The outside of a circle is called the circumference. 
• All points on the circumference of a circle are the same distance from the centre of the circle. This distance is called the radius.
• A circle has an infinite number of lines of symmetry.

Triangle 

• A triangle is a two-dimensional geometric shape. 
• A triangle has 3 sides.
• A triangle has three straight sides. 
• A triangle has three vertices. 
• A triangle is a polygon. 
• The sum of all the angles of a triangle is 180º.

 Quadrilateral  

• A quadrilateral is a two-dimensional geometric shape. 
• A quadrilateral has 4 sides.
• A quadrilateral has four straight sides. 
• A quadrilateral has four vertices. 
• There are six special quadrilaterals: square, rectangle, parallelogram, rhombus, trapezium, and kite. 
• A quadrilateral is a polygon. 

Types of quadrilaterals

Square 

Rectangle

Rhombus 

Parallelogram 

Pentagon 

Hexagon 

PROPERTIES OF 2D SHAPES

• The side of a 2-D shape is the line that forms the outline of the shape. Sides can be straight or curved. A line is another word for a side.
• The corner of a 2-D shape is the point where two sides meet. A corner is also called a vertex, the plural of vertex is vertices.
• Perpendicular lines intersect at a right angle. 
• A regular 2-D shape’s sides and angles are all equal. For example, all the angles in a regular triangle equal 60º.

FUN FACTS

• If a shape has two dimensions, it means there are 2 ways it can be measured in space.
•  All 2D shapes can be measured by their length and width or length and height. 
• But remember, shapes that are 2D are completely flat. For example, the square below is a shape in 2D because it's flat and has straight sides.