Question

please slove this question. ​

Answer 1

Draw a line LM parallel to PQ from O

angle PAO=180-120=60

angle AON=60

angle OBR=180-170=10

angle BON=10

therefore angle AOB=60 + 10=70

Answer 2

Answer:

70°

Step-by-step explanation:

Construction : Draw another line LM parallel to both lines and passes through O.

∵ LM ║ RS       ∴ ∠ MOB + ∠ OBS = 180°

                            ∠ MOB = 180° - ∠ OBS = 180° - 170°

                             ∠ MOB = 10°  

∵ LM ║ PQ       ∴ ∠ MOA + ∠ OAQ = 180°

                            ∠ MOA = 180° - ∠ OAQ = 180° - 120°

                             ∠ MOA = 60°

now   ∠ AOB  =  ∠ MOA + ∠ MOB  =  10° +  60°  =  70°

                             

                                                                                                         thanks