How would I find the coordinates of point A?

If the diagonals of a parallelogram EFGH intersect at pointA.

Would I take the coordinates of E and G and then put it into the equation: (x1+x2)/2 ,(y1+y2)/2 ?

Correct! But continue reading...

The diagonals of a parallelogram intersect at each other's mid-point.
By finding the mid-point of each of the diagonals, you will get the intersection point.
However, it would be wise to check the mid-points of both diagonals to see if they have the same coordinates. If not, EFGH is not a parallelogram (or you have made a mistake in the calculations).

To find the coordinates of point A, where the diagonals of a parallelogram EFGH intersect, you will indeed use the midpoint formula.

First, you need to find the coordinates of the endpoints of the diagonals, E and G. Let's assume E has coordinates (x1, y1) and G has coordinates (x2, y2).

Then, you can use the midpoint formula:

x-coordinate of point A = (x1 + x2) / 2
y-coordinate of point A = (y1 + y2) / 2

Substituting the coordinates of E and G into these equations will allow you to calculate the coordinates of point A.