What shape could be roated about y-axis as shown below to form a square pyramid ?

This shape would be a triangle. You would be able to rotate the triangle around the y axis to create a 3-dimensional object that is a cone.

II

Step-by-step explanation:

The opinions of viewers of one television station are not necessarily representative of the population of a region.

Say a community has a thousand people, not everyone of those people would watch that exact station, among those that do watch which would be a few percentage, only a few also would even care to participate in the said survey.

You can't take a survey based on the responses gotten on just one station