# Asymptote: Useful commands and their Output

For each of the following, we have put a blue dot at the origin in order to indicate relative location of the output on the coordinate plane. In other words, assume that before each of the examples below is the command

```dot((0,0),blue);
```

In addition, a comment after a line such as //math - extension indicates that the command (in this case extension) used in that line is defined in the math package, thus motivating the import math; (or other appropriate package) line at the top of the example.

Example 1:

```dot((20,0));
```

Output 1: $[asy]dot((20,0));[/asy]$

Example 2:

```draw((0,0)--(50,0),BeginArrow);
draw((0,-10)--(50,-10),MidArrow);
draw((0,-20)--(50,-20),EndArrow);
draw((0,-30)--(50,-30),Arrows);
```

Output 2: $[asy] size(75);draw((0,0)--(50,0),BeginArrow); draw((0,-10)--(50,-10),MidArrow); draw((0,-20)--(50,-20),EndArrow); draw((0,-30)--(50,-30),Arrows);[/asy]$

Example 3:

```draw((0,0)--(50,0));
arrow((30,0),dir(180),green);
```

Output 3:

Example 4:

```import math;
pair A,B,C,D,E;
A=(0,0); C=(50,0); B=(10,10); D=(40,20);
E=extension(A,B,C,D);  // math - extension
// extension(A,B,C,D) returns the intersection of lines AB and CD
draw(A--B); draw(C--D);
draw(B--E--D,orange);

```

Output 4:

Example 5:

```import graph;
draw(Circle((0,0),20)); // graph - Circle
```

Output 5:

Example 6:

```path p=(0,0)..(20,15)..(40,-5)..(50,0);
draw(p);
draw(rotate(90)*p,green);
draw(rotate(180,(-5,0))*p,orange);
draw(shift((5,20))*p,magenta);
draw(shift((0,-25))*yscale(1.4)*p,red);
```

Output 6:

Example 7:

```import olympiad;
unitsize(50);
pair A,B,C,O,I;
A=origin; B=2*right; C=1.5*dir(70);
draw(A--B--C--cycle);
dot(O);
dot(I);
label("\$I\$",I,W);
label("\$O\$",O,S);
```

Output 7: $[asy] import olympiad; size(75); pair A,B,C,O,I; A=origin; B=2*right; C=1.5*dir(70); O=circumcenter(A,B,C); /* olympiad - circumcenter */ I=incenter(A,B,C); /* olympiad - incenter */ draw(A--B--C--cycle); dot(O); dot(I); draw(circumcircle(A,B,C)); /* olympiad - circumcircle */ draw(incircle(A,B,C)); /* olympiad - incircle */ label("I",I,W); label("O",O,S); [/asy]$

Example 8:

```import three;
unitsize(1cm);
size(50);
currentprojection=orthographic(1/2,-1,1/2); // three - currentprojection, orthographic
draw((0,0,0)--(1,0,0)--(1,1,0)--(0,1,0)--cycle3,red); //three - cycle3
draw((0,0,0)--(0,0,1));
draw((0,1,0)--(0,1,1));
draw((1,1,0)--(1,1,1));
draw((1,0,0)--(1,0,1));
draw((0,0,1)--(1,0,1)--(1,1,1)--(0,1,1)--cycle3,green);
```

Output 8:

``` import three;
unitsize(1cm);
size(50);
currentprojection=orthographic(1/2,-1,1/2); /* three - currentprojection, orthographic */
draw((0,0,0)--(1,0,0)--(1,1,0)--(0,1,0)--cycle3,red); /*three - cycle3 */
draw((0,0,0)--(0,0,1));
draw((0,1,0)--(0,1,1));
draw((1,1,0)--(1,1,1));
draw((1,0,0)--(1,0,1));
draw((0,0,1)--(1,0,1)--(1,1,1)--(0,1,1)--cycle3,green); (Error compiling LaTeX. 02ee976caa1720f3acc995261e4e55aeaef38cc0.asy: 7.42: no matching variable 'cycle3')```