Question

A boat is moved 80m from the cliff face. The angle of depression of the boat from the top of the cliff is 30 degree. The angle of depression of the anchor on the sea bed from the top of the cliff is 45 .calculate the height of the cliff above sea level and the depth of the sea directly below the boat

Answer 1

tan 30=Height of cliff/80
Height of cliff above sea level
=tan 30×80=46.18m

Height of cliff (from top to sea bed)=tan 45×80=80m

Height of cliff (below sea level)=80-46.18=33.82m

Height of cliff (below sea level)=Depth of sea below the ship=33.82m