The correct option is C 110o
Given−PA&PBaretwotangentstoacirclewithcentreOatA&Brespectively.∠APB=40o.Misapointonthecircumferenceofthecircle.Tofindout−∠AMB=?.Solution−wejoinOA&OB.ThenOA&OBareradiithroughthepointsofcontactA&Bwiththetangenttothegivencircle.∴OA⊥PA&OB⊥PB.i.e∠OAP=90o=∠OBP.∴∠OAP+∠OBP=90o+90o=180o.∴∠AOB+∠APB=360o−(∠OAP+∠OBP)=360o−180o=180o.∴∠AOB=180o−∠APB=180o−40o=140o.∴reflex∠AOB=360o−140o=220o.Nowreflex∠AOBistheangleatthecentreand∠AMBistheangleatthecircumferencesubtendedbythesamearcAMB.∴∠AMB=12×reflex∠AOB=12×220o=110osincetheangle,subtendedbyanarcofacircleatthecentre,isdoubletheanglesubtendedbythesamearcatthecircumferenceofthecircle.Ans−OptionC.