Question

C and D are two observation posts on the same horizontal ground at the foot A of a vertical tower AB.The is 18m due north of D and 24m east of C. The angle of elevation of from D Is 35°. Calculate the height AB
distance CD
angle of elevation of B from
bearing of C from D​

Answer 1

As with all geometry problems, draw a diagram (plan).

You will find that in right triangle ABD, we know

AD=18 m

∠ADB=35°

Solve this triangle to get

mAB=AD tan(ADB)

=18tan(35°)

For right triangle CAB,

mAB (known from above)

mCA = 24m

=>

∠ACB=tan-1(mAB/mCA)

=angle of elevation of B relative to C.

Distance CD can be found by Pythagoras theorem