Question

A ladder 20m long reaches to a distance 20m below from the top of a flagstaff. From the foot of the ladder the elevation of the top of the flagstaff is 60 degree. Find the height of the flagstaff​

Answer 1

Step-by-step explanation:

PB=ladder=BC=20 given.

Also ∠CPA=60

o

∴∠ACP=30

o

∴∠BCP=∠BPC=30

o

as △ABC is isosceles.

∴∠BPA=60

o

−30

o

=30

o

∴AB=30sin30

o

=20.

2

1

=10

Hence the height of flag staff

=AB+BC=10+20=30 ft.