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SAI International School
                                                      CLASS - X

               Mathematics
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               CHAPTER-6: Triangless-3
               HOME ASSIGNMENT-3
                                            m
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               SUBTOPIC :Area of Similar Triangless
                                                                                                        2
                                                                        6 c
                                                                        6 c
                                                             8 c
                                                             8 c
                                  n f
                                                               m
                                  n f
                                                                 , D
                                                               m
                                                                 , D
                                                                    E
                                                                       =

                                                                       =
                                                                                                      m
                                                                    E

                                      gur
                                      gur
                                     i
                                                                                                  45 c
                                     i
                                                     I
                                                   .
                                                   .
                                                     I
                                             E
                                             E
                                                     f
                                               ‖
                                                B
                                                  C
                                                  C
                                                B
                                               ‖


                                                     f
               1.In ΔABC shown in figure, DE ‖ BC. If BC = 8 cm, DE = 6 cm and area of ΔADE = 45 cmm ,
                                          ,
                                          ,
                                                           =
                                         e
                                         e
                                                           =
                                                        C
                                                       B


                                                       B
                                                        C
                                            D
                                            D
                            how
                            how
                     A
                       B
                       B
                                                                                   r
                                                                                   r
                    Δ
                                                                                          A
                                                                                          A
                    Δ
                     A
                                                                                         Δ
                                                                                         Δ
                                                                                       f
                                                                                       f
                                                                                     a
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                         C
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                                                                                    e
                                                                                    e

                           s
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                           s

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                                                                                              E
                                                                              a
                                                                              a
                                                                                              E
                                                                           m

                                                                                                  45 c

                                                                                                =
                                                                           m

                                                                                                =
                                                                                            D
                                                                               nd a
                                                                               nd a
                                                                                            D
               what is the area of ΔABC?

               Ans.80 sq.cm
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                                                                                         he
                                                                    64, w

                                                                              he
                                                                             t
                                                                             t
                                                                              he
                                                                25 :
                                                                25 :
                                                                                 r

                                                                                 r
                                                                          i
                                                                           t
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                                                                         r
                                                                         r
                                                                           t

                                                                    64, w

                                                                           e
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                                                         n r
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                                                                                      of
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                                                 l

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               2.  If the areas of two similar triangles are in ratio 25 : 64, write the ratio of their
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               corresponding sides.
               Ans.5/8

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                                                                            , E
                                                                            , E
                                                                                    c
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                          e
                                                                                              e
                                                                                        a
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                         i


                                                                                              e
                         v
                                                                                     m
                                                                                     m
                                                                                 =
                                                                                 =

                                                                                               a
                                                                                         nd a
                              i
                                                                               F
                                                                               F
                                                                                  4
                                                                                  4
                                                                                        a
                           n f
                       g

                           n f
                                                                                               a
                                                                                                     A
                                                        e
                                                          s
                                                          s
                                            a
                                                       r
                                                        e
                                            a
                                         C
                                                                                                   Δ
                                                           m
                                                             i
                                                             i
                                                          i
                                                          i
                                                           m
                                         C
                                                   E
                                                   E
                                                    F
                                                                                                      B
                                                 D
                                                                                                        C
                                                                                                        C
                                                 D
                                                    F
                                                                                             r
                                            nd Δ
                                                       r
                                                                                                     A
                                            nd Δ
                                                                                                      B
                                                      a
                                                      a
                                                                , B
                                                                , B
                                                                      =
                                                               r
                                                                      =
                                                               r
                                      A
                                                                   C
                                      A
                                    Δ
                                                                                             r
                                                                   C
                                    Δ
                                       B
               3.In the given figure, ΔABC and ΔDEF are similar, BC = 3 cm, EF = 4 cm and area of ΔABC
                                                                                                   Δ
                                       B
                                                                        3
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                                                              l
                                                              a
                                                              a
                                   ,
                       2
                                 ne
                                             f
               = 54 cm . Determine the area of ΔDEF..
                                    t
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                                                D
                                                    F
                        . D
                                               Δ
                                                  E
                              r
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                                         e
                               m
                                         r
                             e

                                          a

                                        a
                           e
                                            o
                                i

               Ans.96 sq.cm
               4.

                                                                                              d
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                                                                                                t
                                                                              A
               ABC is a triangle in which                   , BC = 12 cm and AC = 5 cm. Find the ratio

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                                                                                                      t
                                                                                                    r
                                                                                                    a
                                                                                    5

                                                                                      c

                                                                                  =

                                                                                C

               of the areas of  ANC and  ABC..(Ans.25/144)
                                             B
                                            A
                                               C


                                                                    2
                                                                                              e
               5.In fig5,              , if the area of   xyz is 32 cm , then find the area of the
                                                                                             h
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               quadrilateral PYZQ.
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