1) PQR is a triangular park with PQ=PR=200 m. A TV tower stands at the mid-point of QR. If the angles of elevation of the top of the tower at P,Q and R are respectively 45°,30° and 30° ,then the height of the tower (in m) is A) 100 B) 50 C) 100√3 D) 50√2 Answer: Option AExplanation: Let height of tower TM be h In △PMT.tan45o=TMPM ⇒ 1=hPM ⇒ PM=h In △TQM,tan30o=hQM2 QM=√3h In △PMQ PM2+QM2=PQ2 h2+(√3h)2=2002 ⇒ 4h2=(200)2 ⇒ h=100 m