Question 299279
You can use the Tangent function to find the height of the mountain.
Let h = height of mountain and the horozontal distance to the mountain of 3 miles is the same as the length of the base of the right triangle.
The tangent of the angle of elevation is expressed by {{{h/3}}} 
, so...
{{{Tan(4) = h/3}}} Solve for h.
{{{h = 3*tan(4)}}}
{{{h = 0.20978}}}Miles.
Convert to feet by multiplying by 5,280 ft/mi.
{{{h = 1107.64}}}feet.