CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon


Question

The angles of elevation of the top of a tower from two points at a distance of 4 m and 9 m from the base of the tower and in the same straight line with it are complementary. The height of the tower is ____m.


___


Solution

a + b = 90 (complementary angles)

DB = 4 m

AB = 9 m

Let BC = x (height)

In ΔBCD,

tan b =x4

In ΔABC,

cota =9x

But cota = cot(90 - b) = tan b

Hence, 9xx4 

 x2 = 36 

x = ±  6 

 x = 6, since distance is positive.

So, the height of the building is 6 m.

flag
 Suggest corrections
thumbs-up
 
0 Upvotes


Similar questions
QuestionImage
QuestionImage
View More...


People also searched for
QuestionImage
QuestionImage
View More...



footer-image