Answer:
h = 9 ft
Step-by-step explanation:
Assume the diagram is like the one below.
∆ABD is a right triangle.
We can use Pythagoras' Theorem to find the height h.

It's slope would be undefined.
This means that everybody answered the same number of items. This means that every data value is equal to the mean. This outcome permits us to say that the sample standard deviation of a data set is zero if and only if all of its values are same or identical.
Because all are a multiple of 2, you can factor out 2, 2(-x^2+x+2)=0