10 TEXT : HOME
20 PRINT "Sierpinski triangle using random number generation"
30 PRINT "Press any key to continue"
40 GET A$
100 HGR : HCOLOR=3 : HOME
110 REM set up three points to form a triangle
120 DIM x(3), y(3)
130 x(0) = 0 : y(0) = 160
140 x(1) = 90 : y(1) = 0
150 x(2) = 180 : y(2) = 160
160 REM plot the vertices of the triangle
170 FOR i= 0 to 2
180 HPLOT x(i), y(i)
190 NEXT i
200 REM pick a random starting point
210 x = int(RND(1)*180) : y = int(RND(1)*150)
220 hplot x,y
230 FOR i = 1 to 2000
240 REM randomly pick one of the triangle vertices
250 v = int(rnd(1)*3)
260 REM move the point half way to the triangle vertex
270 x = (x + x(v)) / 2 : y = (y + y(v)) / 2
280 HPLOT x,y
290 NEXT