Step-by-step explanation:
Since Shanika is standing near the pole, we can safely assume that the triangle formed by Shanika and her shadow is a smaller version of the triangle formed by the pole and its shadow.
By similar triangles:
[tex] \frac{x \: of \: pole}{y \: of \: pole} = \frac{x \: of \: shanika}{y \: of \: shanika} \\ \frac{16}{ height \: of \: pole} = \frac{4}{5} \\ 16(5) = 4 \times height \: of \: pole \\ height \: of \: pole = \frac{80}{4} \\ = 20[/tex]
The height of the pole is 20ft.