Solution:
We have to find the height of lamppost
From the figure in question,
Given is a right angled triangle
Where,
base = 40 inches
height = ?
By definition of tan,
[tex]tan\ 70 = \frac{opposite}{base}\\\\tan\ 70 = \frac{height}{40}\\\\height = tan\ 70 \times 40\\\\height = 2.7474 \times 40\\\\height = 109.89 \approx 110[/tex]
Thus height of lamp post to nearest inch is 110 inches