The table shows some values of a function of the form y = ax2 + bx + c.

the value of c, the constant of the function, is
.

Step-by-step explanation:

The table shows that the quadratic function passes through the points (4,21), (5,32) and (6,45).

Substitute the coordinates of those points into the function expression:

Subtract the first equation from the second and the second equation from the third:

Subtract the first equation from the second:

Substitute it into the first equation:

Then,

The quadratic function is

Check remaining two points:

we would need a picture of the quadrilateral in order to answer the question. also, it seems that the question is missing some components.