Find the circumcenter of ABC with A(1,6), B(1,4), and C (5,4)

To find the circumcenter of a triangle, we need to find the intersection point of the perpendicular bisectors of its sides.

First, let's find the midpoint of each side:

The midpoint of AB is ((1+1)/2, (6+4)/2) = (1, 5).

The midpoint of BC is ((1+5)/2, (4+4)/2) = (3, 4).

The midpoint of AC is ((1+5)/2, (6+4)/2) = (3, 5).

Next, let's find the slopes of the perpendicular bisectors of the sides AB, BC, and AC:

The slope of the perpendicular bisector of AB is the negative reciprocal of the slope of AB, which is (6-4)/(1-1) = undefined.

The slope of the perpendicular bisector of BC is the negative reciprocal of the slope of BC, which is (4-4)/(5-1) = 0.

The slope of the perpendicular bisector of AC is the negative reciprocal of the slope of AC, which is (6-4)/(1-5) = -1/2.

Finally, for each perpendicular bisector, let's use point-slope form to find its equation:

The perpendicular bisector of AB passes through the midpoint (1, 5), so its equation is y - 5 = undefined * (x - 1).

Since the slope is undefined, the equation simplifies to x = 1.

The perpendicular bisector of BC passes through the midpoint (3, 4), so its equation is y - 4 = 0 * (x - 3).

Since the slope is 0, the equation simplifies to y = 4.

The perpendicular bisector of AC passes through the midpoint (3, 5), so its equation is y - 5 = -1/2 * (x - 3).

Multiplying through the equation gives you 2y - 10 = -x + 3.

Rearranging the equation gives you x + 2y = 13.

To find the circumcenter, we need to find the intersection point of these three equations.

Solving the system of equations x = 1, y = 4, and x + 2y = 13 gives you x = 1, y = 4.

Therefore, the circumcenter of triangle ABC is at the point (1, 4).