Answer:
The circumcenter is the point

Explanation:
we know that
The circumcenter is the point where the perpendicular bisectors of a triangle intersect
so
In this problem we have
The coordinates of triangle EFG are

Step 1
Find the slope of the side EF
we know that
The formula to calculate the slope between two points is equal to
we have

Substitute the values
-------> the slope is undefined
The side EF is parallel to the y-axis
therefore
The segment perpendicular to the side EF will be parallel to the x-axis
and the equation of the perpendicular bisector to the side EF is equal to the y-coordinate of the midpoint EF
Step 2
Find the y-coordinate of the Midpoint EF
The formula to calculate the y-coordinate of the midpoint between two points is equal to

we have

substitute the values

therefore
the equation of the perpendicular bisector to the side EF is equal to
-------> equation A
Step 3
Find the slope of the side FG
we know that
The formula to calculate the slope between two points is equal to
we have

Substitute the values
The side FG is parallel to the x-axis
therefore
The segment perpendicular to the side FG will be parallel to the y-axis
and the equation of the perpendicular bisector to the side FG is equal to the x-coordinate of the midpoint FG
Step 4
Find the x-coordinate of the Midpoint FG
The formula to calculate the x-coordinate of the midpoint between two points is equal to

we have

substitute the values

therefore
the equation of the perpendicular bisector to the side FG is equal to
-------> equation B
Step 5
Find the intersection point equation A and equation B
we know that
the intersection point of the perpendicular bisector to the side EF and the perpendicular bisector to the side FG is called the circumcenter
-------> equation A
-------> equation B
The solution is the point
