Le triangle A'B'C' est l'image du triangle ABC par l'homothétie de centre I et de rapport k

Déplacer les points I, A,B, et C et observer les mesures des distances et les mesures des angles

Faire varier la valeur de k en deplaçant le curseur et observer les mesures 

A = (2.76, -1.56)
B = (6.464, -0.172)
C = (1.08, 1.62)
poly1, c, a, b = Polygon(A, B, C)
k = -0.7 (slider from -8 to 8, step 0.1)
I = (-1.52, 1.42)
A' = Dilate(A, k, I)
B' = Dilate(B, k, I)
C' = Dilate(C, k, I)
poly1', c', a', b' = Polygon(A', B', C')
d = Segment(I, A)
e = Segment(I, A')
f = Segment(I, C)
g = Segment(I, C')
h = Segment(I, B)
i = Segment(I, B')
distanceA'B' = Distance(A', B')
Midpoint(A', B')
distanceAB = Distance(A, B)
Midpoint(A, B)
TexteAB: Name[A] + (Name[B]) + " \, = \, " + distanceAB
distanceCA = Distance(C, A)
Midpoint(C, A)
TexteCA: Name[C] + (Name[A]) + " \, = \, " + distanceCA
distanceA'C' = Distance(A', C')
Midpoint(A', C')
j: c' / c
l: b' / b
m: e / d
texte3: "Mesures des distances 

AB= " + distanceAB + "                  A'B'=" + distanceA'B' + "
AC=" + distanceCA + "                    A'C'=" + distanceA'C' + "
IA=" + d + "                  IA' =" + e + ""
texte2: "Rapports\ des\ distances : \\
\frac{A'B'}{AB}=" + (LaTeX[j]) + "   \frac{A'C'}{AC}=" + (LaTeX[l]) + "\\
\frac{IA'}{IA}=" + (LaTeX[m]) + ""
α = Angle(B', A', C')
β = Angle(B, A, C)
texte6: "Mesures\ des\ angles: \\
CAB= " + (LaTeX[α]) + "      \ \    C'A'B'=" + (LaTeX[β]) + ""