3D Trig Help (1 Viewer)

[nrlwinner]

A tower stands at the foot of a plane which is inclined to the horizontal at an angle of 12 degrees. A line 100m is measured straight up the incline from the foot of the tower. It is found that at then end of this line the tower subtends at an angle of 62 degrees. Calculate the height of the tower.

If someone can help me draw the diagram, i'd really appreciate it.

 

[Gussy Booo]

What is the answer?

 

[nrlwinner]

What is the answer?

137m (to the nearest metre)

 

[Drongoski]

A tower stands at the foot of a plane which is inclined to the horizontal at an angle of 12 degrees. A line 100m is measured straight up the incline from the foot of the tower. It is found that at then end of this line the tower subtends at an angle of 62 degrees. Calculate the height of the tower.

If someone can help me draw the diagram, i'd really appreciate it.

Assuming tower, height h metres, is vertical, it makes (90 - 12) = 78 deg with inclined plane.

.: in associated triangle, the angle opp the 100 m side = 180 - 78 - 62 = 40 deg

.: h/sin 62 = 100/sin 40 (sine rule) ==> h = 100 sin 62/sin 40 = 137.36 . . . = 137 (nearest m)

PS; this is not a 3D trig problem

 

[khorne]

Assuming tower, height h metres, is vertical, it makes (90 - 121) = 78 deg with inclined plane.

.: in associated triangle, the angle opp the 100 m side = 180 - 78 - 62 = 40 deg

.: h/sin 62 = 100/sin 40 (sine rule) ==> h = 100 sin 62/sin 40 = 137.36 . . . = 137 (nearest m)

PS; this is not a 3D trig problem

Small error: should read 12