First we find the vertex of parabola

The vertex of parabola is

Here,
b = coefficient of x term
a = coefficient of x² term
For given parabola, b = 0 , a = -12
So,

And,

Thus the vertex of parabola is (0, 7)
To find another point on parabola, substitute x by 1.

So the second point on parabola is (1,-5)
The plot of parabola is shown in image below:
I think you mean circumference...Area is

. We have the area so we need to use it to solve for the radius which we will then use in the circumference formula.

. Divide both sides by pi to get

. Of course the simplification of the left side gives us

and r = 4. Now fill that in to the circumference formula, which is

, to get C

which is a circumference of
Answer:
20
Step-by-step explanation:
16 divided by 4/5 = 20 :)
Answer:
Step-by-step explanation:
check the attached document for answer