```---------- ---------- ---------- ---------- ---------- ---------- ---------- ----------

# You can make figures that are not easy to construct with other software.
# How to draw equilateral but not equiangular polygons.

BF=3; HF=3
PLANE(0,10, 0,10); co="brown"
L=5; x1=1; y1=1
a =  80;  Directio(x1,y1, a,L, co); x2=Directionx; y2=Directiony
a =  35;   Directio(x2,y2, a,L, co); x3=Directionx; y3=Directiony
a = -60; Directio(x3,y3, a,L, co); x4=Directionx; y4=Directiony
# Traced three sides, I find the last vertex intersecting the two circles
# of radius L centered on the 1st and the 4th point
Q = circle_circle(x1,y1,L, x4,y4,L); Q
# [1] 3.5362943 5.3089687 5.9277069 0.1528252
x5 = Q[1]; y5 = Q[2]
line(x5,y5, x4,y4, co); line(x5,y5, x1,y1, co)
# I traced the outline; now, if I want, I give color to the polygon
polyC(c(x1,x2,x3,x4,x5),c(y1,y2,y3,y4,y5),"yellow")
#
PLANE(0,10, 0,10); co="brown"
L=6; x1=1; y1=1
a =  90; Directio(x1,y1, a,L, co); x2=Directionx; y2=Directiony
a =   0; Directio(x2,y2, a,L, co); x3=Directionx; y3=Directiony
a = -60; Directio(x3,y3, a,L, co); x4=Directionx; y4=Directiony
Q = circle_circle(x1,y1,L, x4,y4,L); Q
# [1]  5.148757  5.334491  5.851243 -2.530644
x5 = Q[1]; y5 = Q[2]
line(x5,y5, x4,y4, co); line(x5,y5, x1,y1, co)
#
polyC(c(x1,x2,x3,x4,x5),c(y1,y2,y3,y4,y5),"yellow")

```