The meaning of 2-D shapes is 2** dimensional shapes**. In Geometry, a two dimensional shape is defined as a plane figure having two dimensions- length, and breadth (or width). 2 dimensional shapes are also known as rectilinear figures or plane figures. Students can also **download the HD printout of ****Area and Perimeter Formulas of all 2 D Shapes** and can stick on their pinboard. This will help them to revise and learn all the formulas for doing sums on 2-D shapes.

## Area and Perimeter of Plane figures

Before getting into the formulas of area and perimeter of plane figures, let us understand the meaning of Perimeter and Area.**Perimeter: **The perimeter of a plane figure is the length of its boundary.**Area: **The area of a plane figure is the amount of surface enclosed by its sides.In

**simple language,**

**Perimeter is the**

**distance around the outside of a shape and Area is the space inside the shape.**

## Area and Perimeter Formulas of All 2 D Shapes

__Download HD quality printout of Formulas of all 2-D shapes__

**Formulas for Perimeter and Area of Triangle**

A Triangle is a three sided closed and plane figure.

**a**,

**b**, and

**c**be the three sides of a triangle , then

**Perimeter of triangle = (a + b + c) units**

**Area of triangle (Heron’s formula) = √[s(s – a) (s – b) (s – c)]****where s (semi-perimeter) = 1/2 (a + b + c) sq. units**

**Area of triangle = 1/2 × base × height sq. units**

**Area of an equilateral triangle = (√3a2)/4****sq. units**

**Area of an isosceles triangle = b/4****√**(4a2– b2)**sq. units**

**Area of a right-angled triangle = 1/2 × base × height****sq. units**

**Formulas for Perimeter and Area of Parallelogram**

A Parallelgram is a four sided closed figure with opposite sides equal and parallel.

**Perimeter of parallelogram = 2 (sum of adjacent sides)****units**

**Area of parallelogram = (base × correspoding height)****sq. units**

**Formulas for Perimeter and Area of Rhombus**

A Rhombus is a four sided closed figure with all sides equal and opposite sides parallel.

**Area of rhombus = (base × corresponding height)****sq. units**

**Area of rhombus = (1/2 × length of one diagonal × length of other diagonal)****sq. units**

**Perimeter of rhombus = (4 × side) units**

**Formulas for Perimeter and Area of Rectangle**

If

**l**be the length of the rectangle and

**b**its breadth, then

- Perimeter of rectangle = 2(l + b) units

- Area of rectangle = (l × b)
**sq. units**

- Diagonal of rectangle = √(l² + b²) units

**Formulas for Perimeter and Area of Square**

**a**be the length of an edge of a square then,

**Perimeter of square = 4 a units**

**Area of square = a × a =****a2****sq. units**

**Diagonal of square = (√2)a units**

**Perimeter and Area of the Trapezium**

A Trapezium is a four sided closed figure with any one pair of sides parallel to each other.

**Area of trapezium = 1/2 (sum of parallel sides) × (perpendicular distance between them)**

**= 1/2 (a + b) × h sq. units**

**Perimeter = sum of 4 sides**

**Circumference and Area of Circle**

The path traced by a moving point, which always remains at a fixed distance from a fixed point, is called a Circle.

**r**be the radius and

**d**be the diameter of the circle, then

**Diameter (d) = 2r units**

**Circumference of circle = 2πr****= πd (where π = 3.14 or 22/7) units**

**Area of circle = πr²****sq. units**

**Area of ring = Area of outer circle – Area of inner circle**

** = ****π (R² – r²) ****sq. units**

**1 revolution by a circular wheel = circumference of that circular wheel**

**Circumference and Area of Semi-circle**

Every diameter divides a circle into two equal parts, each of which is called a Semi-circle.

**r**be the radius, then

**Circumference of semi-circle = πr + 2r****(where π = 3.14 or 22/7) units****Area of semi-circle = 1/2 πr²****sq. units**