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From a window 20m high above the ground in a street, the angle of elevationand depression of the top and the foot of another house opposite side of thestreet are 60° and 45° respectively. Find the height of opposite house.( Take √ = 1.73) |
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Answer» LET AP 60 m be the height of the window above the ground.(AP = QC) CD = h m be the height of the HOUSE on the opposite side of the Street GIVEN:∠QPD = 60°(angle of elevation of the top of D of house CD) ∠QPC = 45° (angle of depression of the foot C of the house CD) QD = CD - CQ QD = CD - AP [CQ = AP] QD = (h - 60) m In ∆PQC, TAN 45° = QC/PQ = P/B 1 = 60/PQ PQ = 60 m In ∆PQD ,tan 60° = QD/PQ = P/B√3 = (h-60)/6060√3 = (h-60)60√3 +60 = h60(√3+1) = hHence, the height of the opposite house is 60(√3+1) m. |
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