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))
	}
}

C++: #include <complex>
#include <stdio.h>
#include <math.h>
using namespace std;

// _ÀWð^Æ·é
typedef complex<double> P;
// ÎÌè`
#define PI 3.1415926535898

// e·éë·Ã
#define EPS (1e-10)
//
#define X real()
#define Y imag()
	
// Op`NX
class Triangle{

private:
	//Op`ÌR_ÌÀW
	P a, b, c;
	//Op`ÌRÓÌ·³
	double edgeA,edgeB,edgeC;
	//Op`ÌRpÌå«³(WA)
	double angleA,angleB,angleC;
	//Op`ÌÊÏ
	double s;
	//]·è©çRÂÌpxðßéÖ
	double LawOfCosines(double a,double b, double c){
		return acos( (b*b+c*c-a*a) / (2.0*b*c) );
	}
	bool equal(double a, double b){//QÂÌdouble^Ìlªµ¢©Ç¤©
		return (fabs( a-b ) < EPS)? true : false ;
	}
	bool checkRightAngle(double a){//pª¼p©»è·é
		return ( fabs( a-(PI/2.0) ) < EPS )? true : false;
	}

public:
	//RXgN^(RÂÌ_ÆÓÆpxðú»)
	Triangle(P p1, P p2, P p3){
		a = p1;
		b = p2;
		c = p3;
		edgeB = abs(c-a);
		edgeA = abs(b-c);
		edgeC = abs(a-b);
		angleA = LawOfCosines(edgeA,edgeB,edgeC);
		angleB = LawOfCosines(edgeB,edgeC,edgeA);
		angleC = LawOfCosines(edgeC,edgeA,edgeB);
		double hoge;
		hoge = (edgeA+edgeB+edgeC)/2.0;
		s = sqrt(hoge*(hoge-edgeA)*(hoge-edgeB)*(hoge-edgeC));
	}
	
	
	double getAx(){//_AÌXÀWðÔ·
		return a.X;
	}
	double getAy(){//_AÌYÀWðÔ·
		return a.Y;
	}
	double getBx(){//_BÌXÀWðÔ·
		return b.X;
	}
	double getBy(){//_BÌYÀWðÔ·
		return b.Y;
	}
	double getCx(){//_CÌXÀWðÔ·
		return c.X;
	}
	double getCy(){//_CÌYÀWðÔ·
		return c.Y;
	}
	double getEdgeA(){//ÓAÌ·³ðÔ·
		return edgeA;
	}
	double getEdgeB(){//ÓBÌ·³ðÔ·
		return edgeB;
	}
	double getEdgeC(){//ÓCÌ·³ðÔ·
		return edgeC;
	}
	double getAngleA(){//pAÌpx(WA)ðÔ·
		return angleA;
	}
	double getAngleB(){//pBÌpx(WA)ðÔ·
		return angleB;
	}
	double getAngleC(){//pCÌpx(WA)ðÔ·
		return angleC;
	}
	double getArea(){//Op`ÌÊÏðÔ·
		return s;
	}
	double circumscribedCircleRadius(){//OÚ~Ì¼aðÔ·
		return ( edgeA / sin(angleA) / 2.0 );
	}
	double circumscribedCircleX(){//OS(OÚ~ÌS)ÌXÀWðÔ·
		double A = sin(2.0*angleA);
		double B = sin(2.0*angleB);
		double C = sin(2.0*angleC);
		return ( (a.X * A + b.X * B + c.X * C) / (A+B+C) );
	}
	double circumscribedCircleY(){//OS(OÚ~ÌS)ÌYÀWðÔ·
		double A = sin(2.0*angleA);
		double B = sin(2.0*angleB);
		double C = sin(2.0*angleC);
		return ( (a.Y * A + b.Y * B + c.Y * C) / (A+B+C) );
	}
	double incenterRadius(){//àÚ~Ì¼aðÔ·
		return ( (2.0*s) / (edgeA+edgeB+edgeC) );
	}
	double incenterX(){//àS(àÚ~ÌS)ÌXÀWðÔ·
		return ( (edgeA*a.X+edgeB*b.X+edgeC*c.X) / (edgeA+edgeB+edgeC) );
	}
	double incenterY(){//àS(àÚ~ÌS)ÌYÀWðÔ·
		return ( (edgeA*a.Y+edgeB*b.Y+edgeC*c.Y) / (edgeA+edgeB+edgeC) );
	}
	double centerOfGravityX(){//dSÌXÀWðÔ·
		return ( (a.X+b.X+c.X) / 3.0 );
	}
	double centerOfGravityY(){//dSÌYÀWðÔ·
		return ( (a.Y+b.Y+c.Y) / 3.0 );
	}
	bool checkRightTriangle(){//¼pOp`©Ç¤©»è·é
		if(checkRightAngle(angleA)||checkRightAngle(angleB)||checkRightAngle(angleC)){
			return true;
		}else{
			return false;
		}
	}
	bool checkIsoscelesTriangle(){//ñÓOp`©»è·é 
		if( equal(angleA,angleB) || equal(angleB,angleC) || equal(angleC,angleA) ){
			return true;
		}else{
			return false;
		}
	}
	bool checkEquilateralTriangle(){//³Op`©»è·é 
		if( equal(edgeA,edgeB) && equal(edgeB,edgeC) && equal(edgeC,edgeA)){
			return true;
		}else{
			return false;
		}
	}
};

int main(){
	int n;
	double ax,ay,bx,by,cx,cy;
	scanf("%d", &n);
	for(int i=0 ; i<n ; i++){
		scanf("%lf %lf %lf %lf %lf %lf", &ax,&ay,&bx,&by,&cx,&cy);
		P a(ax,ay), b(bx,by), c(cx,cy);
		Triangle Tr(a,b,c);
		printf("%.3f %.3f ", (float)Tr.circumscribedCircleX(), (float)Tr.circumscribedCircleY());
		printf("%.3f\n", (float)Tr.circumscribedCircleRadius() );
	}
	return 0;
}