# Difference between revisions of "A 5-circle incidence theorem"

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This is a visualization of A 5-Circle Incidence Theorem by J. Chris Fisher, Larry Hoehn and Eberhard. M. Schröder, Mathematics Magazine, Volume 87, 2014 - Issue 1.

### The underlying JavaScript code

var board = JXG.JSXGraph.initBoard('jxgbox',{boundingbox:[-5,5,5,-5]});
var A = [], s = [], B = [], c = [], r = [], k;

var attA = {name:'',strokeColor: '#7355ff', fillColor: '#7355ff'};
A = board.create('point', [2.5, -3], attA);
A = board.create('point', [2, 4], attA);
A = board.create('point', [-2.5, 3], attA);
A = board.create('point', [-4, -2], attA);
A = board.create('point', [0, -4], attA);

for (k = 0; k < 5; k++) {
s[k] = board.create('segment',[A[k], A[(k + 2) % 5]],{strokeColor:'blue',strokeWidth:1});
}

var attB = {name: '', strokeColor: '#EA0000', fillColor: '#EA0000'};
for (k = 0; k < 5; k++) {
B[k] = board.create('intersection', [s[k], s[(k-1+5)%5], 0], attB);
}

var attC = {strokeColor: '#aaaaaa', strokeWidth: 1};
for (k = 0; k < 5; k++) {
c[k] = board.create('circle', [A[k], B[k], A[(k+1)%5]], attC);
}

var attR = {strokeColor: '#ff0000', strokeWidth: 2};
for (k = 0; k < 5; k++) {
r[k] = board.create('radicalaxis', [c[k], c[(k-1+5)%5]], attR);
}