Question

A lighthouse sits at the edge of a cliff, as shown. A ship at sea level is meters from the base of the cliff. The angle of elevation from sea level to the base of the lighthouse is . The angle of elevation from sea level to the top of the lighthouse is . Find the height of the lighthouse from the top of the cliff. Do not round any intermediate computations. Round your answer to the nearest tenth. Note that the figure below is not drawn to scale.

Answer 1

There is no numbers provided, but this is how you solve it.

We can use the tangent function to solve for the height of the lighthouse.

Let h be the height of the lighthouse from the top of the cliff.

tan(angle of elevation from sea level to the top of the lighthouse) = (h+ height of lighthouse from sea level ) / distance from the base of the cliff

tan( angle of elevation from sea level to the top of the lighthouse) = (h+x) / distance from the base of the cliff

tan(angle of elevation from sea level to the base of the lighthouse) = (h) / distance from the base of the cliff

By dividing the first equation by the second equation

(h+x) / distance from the base of the cliff = tan( angle of elevation from sea level to the top of the lighthouse) / tan( angle of elevation from sea level to the base of the lighthouse)

(h+x) = (h) * (tan( angle of elevation from sea level to the top of the lighthouse) / tan( angle of elevation from sea level to the base of the lighthouse))

h = (x * tan( angle of elevation from sea level to the base of the lighthouse)) / ( tan( angle of elevation from sea level to the top of the lighthouse) - tan( angle of elevation from sea level to the base of the lighthouse))

After plugging in the values into the equation, we get:

h = (x * tan( )) / ( tan( ) - tan( ))

Round to the nearest tenth

h = (x * tan( )) /