Go: package main

import (
	"bufio"
	"fmt"
	"io"
	"math"
	"os"
	"strconv"
	"strings"

)


func main() {
	solve(os.Stdin, os.Stdout)
}

type ReaderEx struct {
	baseScanner *bufio.Scanner
	words       []string
	nextWordIdx func() int
	initWordIdx func(int)
}

func NewScannerEx(stdin io.Reader) *ReaderEx {
	var this ReaderEx
	var idx int
	var wordsCnt int
	this.baseScanner = bufio.NewScanner(stdin)
	this.baseScanner.Buffer(make([]byte, 0), 1E+11)
	this.nextWordIdx = func() int {
		cur := idx
		idx = (idx + 1) % wordsCnt
		return cur
	}
	this.initWordIdx = func(wc int) {
		idx = 0
		wordsCnt = wc
	}
	return &this
}

func (me *ReaderEx) Scan(doSplit bool) (isScanned bool) {
	isScanned = me.baseScanner.Scan()
	if doSplit {
		me.words = strings.Fields(me.baseScanner.Text())
	} else {
		me.words = []string{me.baseScanner.Text()}
	}
	me.initWordIdx(len(me.words))
	return
}

func (me *ReaderEx) nextBytes() []byte {
	return []byte(me.words[me.nextWordIdx()])
}
func (me *ReaderEx) nextString() string {
	return me.words[me.nextWordIdx()]
}

type StringArray []string

func (me *ReaderEx) nextStringArray() StringArray {
	return me.words[me.nextWordIdx():]
}

func (me StringArray) toStrings() []string {
	return me
}

func (me StringArray) toInts() []int {
	strValues := me.toStrings()
	values := make([]int, len(strValues))
	for i, v := range strValues {
		n, err := strconv.Atoi(v)
		if err != nil {
			panic(err)
		}
		values[i] = n
	}
	return values
}
func (me *ReaderEx) nextInt() int {
	n, err := strconv.Atoi(me.words[me.nextWordIdx()])

	defer func() {
		if err != nil {
			panic(fmt.Sprintf("getInt(%d)", n))
		}
	}()
	return n
}

func pow(x, y, mod int) (ans int) {

	ans = 1
	for bit := 1 << uint(math.Floor(math.Log2(float64(y)))); ; bit >>= 1 {
		if y&bit != 0 {
			ans *= x
			if mod > 0 {
				ans %= mod
			}
		}
		if bit <= 1 {
			return
		}
		ans *= ans
		if mod > 0 {
			ans %= mod
		}
	}
}

type factType struct {
	prime int
	count int
}

func fact(n int) (facts []*factType) {

	for i := 2; i*i <= n; i++ {
		if n%i == 0 {
			fa := factType{prime: i}
			for n%fa.prime == 0 {
				n /= fa.prime
				fa.count++
			}
			facts = append(facts, &fa)
		}
	}
	if n > 1 {
		facts = append(facts, &factType{prime: n, count: 1})
	}
	return facts
}
func dec2bin(n int) (ret []bool) {
	for bit := 1 << uint(math.Floor(math.Log2(float64(n)))); ; bit >>= 1 {
		ret = append(ret, n&bit != 0)

		if bit <= 1 {
			return
		}
	}

}

func abs(v int) int {
	if v < 0 {
		v = -v
	}
	return v
}

func b2i(b bool) (i int) {
	if b {
		i = 1
	} else {
		i = 0
	}
	return
}

func solve(stdin io.Reader, stdout io.Writer) {

	r := NewScannerEx(stdin)
	r.Scan(true)
	n := r.nextInt()

	type Vec struct {
		x, y float64
	}
	vec := func(a, b Vec) Vec { return Vec{b.x - a.x, b.y - a.y} }
	unv := func(a Vec) Vec { return Vec{-a.y, a.x} }
	cdot := func(a, b Vec) float64 { return a.x*b.x + a.y*b.y }
	times := func(t float64, a Vec) Vec { return Vec{t * a.x, t * a.y} }
	add := func(a, b Vec) Vec { return Vec{a.x + b.x, a.y + b.y} }
	for i := 0; i < n; i++ {

		r.Scan(true)
		nextFloat64 := func() (ret float64) { fmt.Sscanf(r.nextString(), "%f", &ret); return }
		a1, a2, a3 := Vec{nextFloat64(), nextFloat64()}, Vec{nextFloat64(), nextFloat64()}, Vec{nextFloat64(), nextFloat64()}
		unv23 := unv(vec(a2, a3))
		v12 := vec(a1, a2)
		v31 := vec(a3, a1)
		s := cdot(v12, v31) / 2 / cdot(v12, unv23)
		c := add(times(.5, add(a2, a3)), times(s, unv23))
		v1c := vec(a1, c)
		fmt.Fprintf(stdout, "%.3f %.3f %.3f\n", c.x, c.y, math.Sqrt(v1c.x*v1c.x+v1c.y*v1c.y))
	}
}

Python: #!/usr/bin/env python
# -*- coding:utf-8 -*-
import sys

n = int(sys.stdin.readline())
for i in range(n):
    x1,y1,x2,y2,x3,y3 = list(map(float, sys.stdin.readline().split()))
    a = ((x3-x2)**2 + (y3-y2)**2)**0.5
    b = ((x1-x3)**2 + (y1-y3)**2)**0.5
    c = ((x2-x1)**2 + (y2-y1)**2)**0.5
    r = a*b*c / ((a+b+c) * (-a+b+c) * (a-b+c) * (a+b-c))**0.5
    a2,b2,c2 = a**2,b**2,c**2
    x = (a2*(b2+c2-a2)*x1 + b2*(c2+a2-b2)*x2 + c2*(a2+b2-c2)*x3) / \
        (a2*(b2+c2-a2) + b2*(c2+a2-b2) + c2*(a2+b2-c2))
    y = (a2*(b2+c2-a2)*y1 + b2*(c2+a2-b2)*y2 + c2*(a2+b2-c2)*y3) / \
        (a2*(b2+c2-a2) + b2*(c2+a2-b2) + c2*(a2+b2-c2))
    print("{:.3f} {:.3f} {:.3f}".format(x,y,r))

Python: for _ in[0]*int(input()):
 a,b,c,d,e,f=map(float,input().split())
 x=((a*a+b*b)*(d-f)+(c*c+d*d)*(f-b)+(e*e+f*f)*(b-d))/2/(a*(d-f)+c*(f-b)+e*(b-d))
 y=((a*a+b*b)*(c-e)+(c*c+d*d)*(e-a)+(e*e+f*f)*(a-c))/2/(b*(c-e)+d*(e-a)+f*(a-c))
 print(f"{x:.4} {y:.4} {(x*x+y*y)**.5:.4}")

Python: for _ in[0]*int(input()):
 a,b,c,d,e,f=map(float,input().split())
 x=((a*a+b*b)*(d-f)+(c*c+d*d)*(f-b)+(e*e+f*f)*(b-d))/2/(a*(d-f)+c*(f-b)+e*(b-d))
 y=((a*a+b*b)*(c-e)+(c*c+d*d)*(e-a)+(e*e+f*f)*(a-c))/2/(b*(c-e)+d*(e-a)+f*(a-c))
 print('%.3f %.3f %.3f'%(x,y,((x-a)**2+(y-b)**2)**.5))

Python: import math
for _ in range(int(input())):
    x1,y1,x2,y2,x3,y3=map(float,input().split())
    a,b,c=2*(x2-x1),2*(y2-y1),x1**2-x2**2+y1**2-y2**2
    aa,bb,cc=2*(x3-x1),2*(y3-y1),x1**2-x3**2+y1**2-y3**2
    x,y=(b*cc-bb*c)/(a*bb-aa*b),(c*aa-cc*a)/(a*bb-aa*b)
    print('%.3f %.3f %.3f'%(x,y,math.hypot(x1-x,y1-y)))

Python: import math

N = int(input())

for l in range(N):
    x1,y1,x2,y2,x3,y3 = [float(i) for i in input().split()]

    # ax + by = e
    # cx + dy = f

    a,b,c = x1-x2, y1-y2, (x1-x2)*(x1+x2)/2 + (y1-y2)*(y1+y2)/2
    d,e,f = x1-x3, y1-y3, (x1-x3)*(x1+x3)/2 + (y1-y3)*(y1+y3)/2

    X = (c*e-f*b)/(a*e-b*d)
    Y = (f*a-c*d)/(a*e-b*d)
    R = math.sqrt((X-x1)*(X-x1)+(Y-y1)*(Y-y1))

    print(format(X, '.3f'), format(Y, '.3f'), format(R, '.3f'))

Python: def main():
	import math
	n = int(input())
	w = [0]*6

	for _ in range(n):
		x1, y1, x2, y2, x3, y3 = map(float, input().split())
		w[0] = 2*(x2-x1)
		w[1] = 2*(y2-y1)
		w[2] = x2**2 + y2**2 - x1**2 - y1**2
		w[3] = 2*(x3-x1)
		w[4] = 2*(y3-y1)
		w[5] = x3**2 + y3**2 - x1**2 - y1**2

		x, y = solve(w)

		r = math.sqrt((x-x1)**2 + (y-y1)**2)

		print("{:.3f} {:.3f} {:.3f}".format(x, y, r))


def solve(w):
	x = (w[2]*w[4]-w[1]*w[5]) / (w[0]*w[4]-w[1]*w[3])
	y = (w[2]*w[3]-w[0]*w[5]) / (w[1]*w[3]-w[0]*w[4])
	x = round(x, 3)
	y = round(y, 3)
	if x == -0.0:
	    x = 0.0
	if y == -0.0:
	    y = 0.0
	return x, y


if __name__ == '__main__':
	main()

Python: from math import sqrt
for _ in range(int(input())):
    x1, y1, x2, y2, x3, y3= map(float, input().split())
    a= sqrt((x3-x2)**2 + (y3-y2)**2)
    b= sqrt((x3-x1)**2 + (y3-y1)**2)
    c= sqrt((x2-x1)**2 + (y2-y1)**2)
    numerator, denominator= 2*b*c, b**2 + c**2 - a**2
    cosA= denominator / numerator
    sinA= sqrt(1 - (cosA)**2)
    r= a / (2*sinA)
    px= (x2-x1) / 2
    py= (y3-y1) / 2
    print(px, py, r)

Python: from math import sqrt
def g(x):
    y = (((1000 * x) * 2 + 1) // 2) / 1000
    return y
def f(x):
    a = (x[2] - x[4]) * (x[1] - x[3]) - (x[0] - x[2]) * (x[3] - x[5])
    b = (x[0] - x[2]) * (x[4] - x[0]) - (x[5] - x[1]) * (x[1] - x[3])
    l = 0.5 * b / a
    X = 0.5 * x[2] + 0.5 * x[4] + l * (x[3] - x[5])
    Y = 0.5 * x[3] + 0.5 * x[5] + l * (x[4] - x[2])
    R = sqrt((X - x[0]) ** 2 + (Y - x[1]) ** 2)
    X = g(X)
    Y = g(Y)
    R = g(R)
    print("{0:.3f} {1:.3f} {2:.3f}".format(X, Y, R))
n = int(input())
a = []
for _ in range(n):
    a.append(list((map(float, input().split()))))
for i in a:
    f(i)