User:Bjc
[center][b]bjc's Entry:[/b][/center]
3-4-5 triangle with circumcircle/center, incircle/center, orthocenter, centroid and 3 excircles
[asy]
size(12cm);
dot((0,0));
dot((4,0));
dot((0,3));
dot((2,1.5));
dot((1,1));
dot((1.333,1));
dot((6,6));
dot((-2,2));
dot((3,-3));
draw((0,0)--(4,0)--(0,3)--(0,0));
draw((0,3)--(2,0));
draw((4,0)--(0,1.5));
draw(circle((2,1.5) , 2.5));
draw(circle((1,1) , 1));
draw(circle((6,6) , 6));
draw(circle((-2,2) , 2));
draw(circle((3,-3) , 3));
draw((-2,4.5)--(8,-3));
draw((0,0)--(2,1.5));
draw((0,-4.5)--(0,6.5));
draw((-2.5,0)--(6.5,0));
label( "" , (0,0), SW);
label( "
" , (4,0), E);
label( "
" , (0,3), N);
label( "
" , (1.33333,1) , S);
label( "
" , (2,1.5), NE);
label( "
" , (0,0)--(0,3) , W);
label( "
" , (0,0)--(4,0) , S);
label( "
" , (0,4.6)--(3.9,0));
label( "
" , (1,1) , W);
label( "
" , (6,6) , SW);
label( "
" , (-2,2) , SW);
label( "
" , (3,-3) , S);
[/asy]