Answer:
Let the distance of the cliff from the boat be y and height of the top of the cliff be x.
As per the statement:
From a boat on the lake, the angle of elevation to the top of a cliff is 26°1'. If the base of the cliff is 205 feet from the boat.
⇒y = 205 feet, 
We have to find the high is the cliff i,e x.
Using tangent ratio:

See the diagram as shown below:
Opposite side = x feet
adjacent side = 205 feet
Using conversion:

then;

Substitute these values we have;

Multiply both sides by 205 we have;
ft
Therefore, 100 ft high is the cliff(to the nearest foot)