Page 9 - Ans Sub
P. 9

11.  In the given figure, AB || PQ. Find the values of x and y.



















                     Solution:
                     It is given that AB || PQ and EF is a transversal
                     From the figure we know that ∠CEB and ∠EFQ are corresponding angles
                     So, we get
                                          0
                     ∠CEB = ∠EFQ = 75
                     It can be written as
                                 0
                     ∠EFQ = 75
                     Where
                                          0
                     ∠EFG + ∠GFQ = 75
                        0
                            0
                                   0
                     25  + y  = 75
                                 0
                            0
                      0
                     y  = 75 - 25
                      0
                            0
                     y = 50
                     From the figure we know that ∠BEF and ∠EFQ are co-interior angles.
                     So, we get
                                           0
                     ∠BEF + ∠EFQ = 180
                                        0
                                 0
                     ∠BEF + 75  = 180
                                        0
                                  0
                     ∠BEF = 180  - 75
                                  0
                     ∠BEF = 105
                     We know that ∠BEF can be written as
                     ∠BEF = ∠FEG + ∠GEB
                         0
                                         0
                     105  = ∠FEG + 20
                                        0
                                  0
                     ∠FEG = 105  - 20
                                 0
                     ∠FEG = 85
                     Now, in △ EFG,
                                             0
                            0
                      0
                     x  + 25 + ∠FEG = 180
                                 0
                      0
                                         0
                            0
                     x + 25 + 85  = 180
                                   0
                              0
                                         0
                      0
                     x  = 180  - 25  - 85
                                     0
                      0
                              0
                     x  = 180  – 110
                            0
                      0
                     x = 70
                                                     0
                     Therefore, the value of x is 70 .

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