Simple quadratic function, but can't understand the question

Question

I have a very very simple quadratic function:

Now building a new tunnel that has a shape of parabolic curve. The tunnel is 10 m wide and at 4 m from either side, the height of the tunnel is 6 m. Find the quadratic equation in standard form that models the ceiling of the new tunnel.

The question is very simple, but I just can't understand what does at 4 m from either side mean in this question while mentioning the width in 10m?

I am not a native English speaker so it is hard for me understand what the information this question is asking.

Any comments and answers will be appreicated!

Edit: I see comments where people say that this question is badly word, I agree. Actually, this is a question I did on test and I just get the result today, none of the people in my class get the answer.

It not me made the question.

Answer 1

This figure would help you understand:

(To-scale figure,Credit :Dan)

Answer 2

$$f(0)=f(10)=0$$

$$f(4)=f(10-4)=6$$

The tunnel is 10 m wide and at 4 m from either side, the height of the tunnel is 6 m.

The sentence is split into two parts by the "and", not by the comma.