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SAI International School
                                                       CLASS - IX

               Mathematics
               CHAPTER-12: Heron’s Formula

                Worksheet-1


               SUBTOPIC: Area of Triangle-by Heron’s Formula

               1.    The sides of a triangle are in the ratio of 3:5: 7 and its perimeter is 300 cm.Its     1
                     area will be:

                     a. 1000√3 cm b. 1500√3 cm c. 1700√3  cm d. 1900√3 cm
                                   2
                                                                                  2
                                                                   2
                                                   2
               2.    Find the area of a triangle whose base and altitude are 5 cm and 4 cm                  1
                     respectively.
               3.    The area of an equilateral triangle with side 2√3 cm is__________.                     1

               4.    The sides of a triangle are 15 cm, 17 cm and 8 cm.  Its area is:                       1

                               2
                        a. 20cm b. 40cm  2           c. 60cm 2                d. 80cm 2

               5.    If area of the hexagon is 24√3      , find its perimeter.                              1
                                                         2
                                                                2
               6.    An isosceles right triangle has area 8 cm . Find the length of its hypotenuse.         1
               7.     Find the perimeter and area for the given equilateral triangle.                       2



















               8.     Find the area of a right-angled triangle, if the radius of its circumcircle is 2.5    2
                      cm and the altitude drawn to the hypotenuse is 2 cm long.



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