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What are the coordinates of the circumcenter of a triangle with vertices A(1,5)A(1,5), B(3,3)B(3,3), and C(3,5)C(3,5)?

User AnatolyS
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Circumcenter of a triangle is the intersection point of the perpendicular bisectors of the three sides.

Perpendicular bisector of a line segment is a line passing through the mid-point of the line segment and is perpendicular to it.


Perpendicular bisector of AB:
Mid-point of AB, M(−3+32, 4+42−3+32, 4+42)

Coordinates of M(0, 4)0, 4)

Gradient or slope of AB, m = 4−4−3−3 =04−4−3−3 =0

Gradient or slope of line perpendicular to AB = 1m =∞1m =∞

⇒⇒ Perpendicular line to AB is a vertical line on xy plane.

Perpendicular bisector of AB is a vertical line passing through M(0,4). It's equation: x=0 ----------Line 1


Perpendicular bisector of BC:
Mid-point of BC, N(3+(−4)2, 4+(−3)23+(−4)2, 4+(−3)2)

Coordinates of N(12, 12)12, 12)

Gradient or slope of BC, m = −3−4−4−3 =1−3−4−4−3 =1

Gradient or slope of line perpendicular to BC = 1m =−11m =−1

Perpendicular bisector of BC is a line passing through N (12, 1212, 12) and is having a slope -1.

Equation of perpendicular bisector of BC:

y−12 =−1(x−(−12))y−12 =−1(x−(−12))

y−12 =−x−12y−12 =−x−12

y = x --------- Line 2

Circumcenter is point of intersection of Line 1 and Line 2.

x= 0, y =0
User Danial Dezfooli
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