110k views
2 votes
the angle of elevation of the top of a tower from a point 42m away from the base on level ground is 36 find the height of the tower​

User Smaranjit
by
5.3k points

1 Answer

4 votes

Answer:

30.51 meters

Explanation:

Given that:

The distance from the point to the base of the tower = 42 m, the angle of elevation = 36°.

According to sine rule if a,b,c are the sides of a triangle and its respective opposite angles are A, B, C. Therefore:


(a)/(sin(A)) =(b)/(sin(B))=(c)/(sin(C))

Let the height of the tower be a and the angle opposite the height be A = angle of elevation = 36°

Also let the distance from the point to the base of the tower be b = 42 m, and the angle opposite the base of the tower be B

To find B, since the angle between the height of the tower and the base is 90°, we use:

B + 36° + 90° = 180° (sum of angles in a triangle)

B + 126 = 180

B = 180 - 126

B = 54°

Therefore using sine rule:


(a)/(sin(A)) =(b)/(sin(B))\\\\(a)/(sin(36))=(42)/(sin(54))\\\\ a=(42*sin(36))/(sin(54))\\ \\a=30.51\ meters

The height of the tower is 30.51 meters

User Amorphic
by
5.1k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.