Question -
Answer -
In тИЖABC, sides BC, CA and BA are produced to D, E and F respectively.
тИаACD = 105┬░ and тИаEAF = 45┬░
тИаACD + тИаACB = 180┬░ (Linear pair)
тЗТ 105┬░ + тИаACB = 180┬░
тЗТ тИаACB = 180┬░- 105┬░ = 75┬░
тИаBAC = тИаEAF (Vertically opposite angles)
= 45┬░
But тИаBAC + тИаABC + тИаACB = 180┬░
тЗТ 45┬░ + тИаABC + 75┬░ = 180┬░
тЗТ 120┬░ +тИаABC = 180┬░
тЗТ тИаABC = 180┬░- 120┬░
тИ┤ тИаABC = 60┬░
Hence тИаABC = 60┬░, тИаBCA = 75┬░
and тИаBAC = 45┬░