Question
a man measured the angle of elevation of the top of a tower to be 70 degree. When he walked 300 m. further, the angle of elevation of the top was 35 degree. What is the height of the tower?
Answers
Reiny
make a diagram
label the tower AB , where A is the top of the tower.
label the man's first position C, his second position D
so that DC = 300
Look at triangle ADC,
angle D = 35°
angle ACD = 110° , so then
angle DAC = 35°
so the triangle is isosceles (lucky) and AC = 300
Then in the right-angled triangle ACB ,
sin70 = AB/300
AB = 300sin70 = 281.9 m
(had the triangle not been isosceles, I would have used the Sine Law to find AC )
label the tower AB , where A is the top of the tower.
label the man's first position C, his second position D
so that DC = 300
Look at triangle ADC,
angle D = 35°
angle ACD = 110° , so then
angle DAC = 35°
so the triangle is isosceles (lucky) and AC = 300
Then in the right-angled triangle ACB ,
sin70 = AB/300
AB = 300sin70 = 281.9 m
(had the triangle not been isosceles, I would have used the Sine Law to find AC )
Anonymous
A BOY OBSERVED THAT THE ANGLE OF ELEVATION OF THE TOP OF A TOWER IS 32 Degree HE THEN WALKS 8m Towards The Tower And THEN DISCOVER THAT THE OF Angle Of Elevation Is 43degree .Find The Height Of The Tower