Question

The angal of elevation of the and bottom of a flagstaff fixed on a building are 45°and 30° respectively as observed ba a man standing on other end of a 15 m wide road find the haight of the flagstaff

Answer 1

Answer:

Let AB is the tower of height x m and BC is the flagstaff of height 10 m. Let D be the point from where the angles of elevation are 450 and

600 such that BDA = 450 and CDA = 600

In DAB, tan 450 = AB/AD

1 = x/AD AD = x

In DAC, tan 600 = AC/AD

3

= (10+x)/x3

x = 10+x

( 3 -1)x = 10

x = 10/( 3 - 1) = 10/(3- 1) x (3+ 1)/( 3+ 1)x = 5( 3+ 1)