How tall is a building that casts a 73 foot shadow when the angle of elevation of the sun is 29

We use trigonometry for this problem. You might have learned about SOH CAH TOA. In right triangles, when given an angle, you can name the three sides of the triangle a certain part: Opposite, Adjacent, and Hypotenuse.

For this problem, we are given the angle and the ADJACENT length (73). We want to find the OPPOSITE side's length.
TOA
We must use the tangent function.

TOA helps us remember this relationship:
tan( theta ) = opposite / adjacent.

Plug in our values:

tan(29 degrees) = opposite / 73

Multiply by 73 to isolate "opposite" and solve for it.

73 * tan(29) = opposite.

Using a calculator, the answer is approximately 40.46 ft.