Question 106714
You can think of this situation in terms of a right triangle whose height is that of the bulding (115m) and whose base is the building's shadow (24m)
The angle of elevation (A) of the top of the building (this is the angle between the base and the hypotenuse or the angle of the sun) is the angle whose tangent is 115m over 24m. So you can express this as:
{{{Tan^(-1)(A) = 115/24}}} This known as the arctangent of angle A
Most scientific calculators have the three main trig functions and their inverses.
The arctangent (or inverse tangent) function will probably be labeled as {{{Tan^(-1)}}} or as Arctan.
In the TI-86, I get the following result:
{{{Tan^(-1)(115/24) = 78.21}}}