Area Irregular Figure : 2

    Irregular figure is defined as which figure is all the angles are not equal measure and all the sides are not same length, is called as irregular figure or irregular polygon. Unlike a regular shape figure, there is no separate or easy formula for the area of an irregular figure. So we will break the given figure into some pieces then we can find the area of irregular figure : 2.

Finding area of 2 irregular figures using examples::

 

           In irregular figure or polygon, all the sides could be a different length, and all angles could not be same (different). It could be also either concave or convex.

       Example: irregular figure (or) polygon. 

          irregular figure

 

 

How to find Area of irregular figure:2

 

      Let us use this figure (irregular polygon) as example: 

     

         In the above figure is L - shape, but there is irregular shape, find the area of this figure:

 Solution:

           We know well how to find the area of a regular figure (or) polygon, so we just subtract the area of small rectangle from the large rectangle figure. Otherwise we can cut the area up to non- overlapping rectangle and add their areas,

 Figure:

              

Calculate the area of above irregular figure:

 Area = (2*4) + (2 + 3)*2

           = (8) + (5)*2

           = 8 + 10

So, we have to get,

 A   = 18         

 In other way we have to find this irregular figure area in to

      A= (2+3) * (4+2) – (3*4)

                = (5) * (6) – (12)   

                = 30 – 12

               A = 18  

 2. Example:

           Let us use this figure to find the area shaded in blue (irregular polygon) as example: 

Solution:

            Just calculate the area of small rectangle, and area of large rectangle, then subtracts the small value from large value.

  Step 1.  Area of large rectangle:

                  A = L * B

                     = 10 * 5

       Area 1 = 50

Step 2.  Area of small rectangle:

               A = L * B

                   = 4* 2

     Area 2 = 8

 Step 3.  Subtract large rectangle value to small value:

                 Area 1 - Area 2

                 50 – 8 = 42

    Area of irregular figure is 42.