Page 172 - Math Skill - 5
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170                                                                                                  Maths


        Area of Composite Figures having Rectangles and Squares
        We have learnt how to find the area of a square and a rectangle. But every figure cannot be as
        simple as a square or a rectangle. There are figures which are formed by the combination of two
        or more rectangles or squares or both.

        Area of such figures is determined by separating all the squares and rectangles, calculating
        their areas and then adding up.



              Let’s Attempt
        Example 1:  Find the area of the adjoining figure.

        Solution:      The  adjoining  figure  is  the  floor  of  an  L-shaped
                       room.  To  find  the  area  of  this  floor,  we  divide  it
                       into two rectangles marked as P and Q and find the
                       area of each rectangle separately and then add the
                       two to find the area of the total floor.

                       Thus, area of the rectangle P  = 8 m × 5 m = 40 sq m
                       Area of rectangle Q               = 3 m × 1.5 m = 4.5 sq m

                       Total area of the floor           = (40 + 4.5) sq m = 44.5 sq m.

                       The area of the figure is 44.5 sq m.
        Example 2:   The figure alongside shows a rectangular park with
                       a pathway around it (shown as shaded). Length

                       and breadth of the park along with pathway are                 21 m         24 m     15 m
                       27 m and 21 m  respectively. Excluding the
                       pathway, length and breadth of the park are 24 m
                       and 15 m respectively. Find the area of the pathway.                         27 m
        Solution:      Area of the park including the pathway  = Length × Breadth

                                                                      = 27 m × 21 m = 567 m    2

                       Area of the park excluding pathway  = Length × Breadth
                                                                  = 24 m × 15 m = 360 m    2
                       Area of the pathway

                            =  Area of the park including pathway – Area of the park excluding pathway

                            =  567 m  – 360 m  = 207 m .
                                     2
                                                          2
                                                2
                       The area of the pathway is 207 m .
                                                             2
        Example 3:   Find the area of the figure shown on the next page.
        Solution:        The figure shown is made up of 3 rectangles marked as P, Q and R.

                       For rectangle P:  Length = 12 cm, Breadth = 6 cm
                       For rectangle Q:  Length = 12 cm, Breadth = 6 cm
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