d = 1 (slider from 0.1 to 5, step 0.5)
A = (0, 0)
C = Point(yAxis)
n = 100 (slider from 2 to 100, step 1)
a_1 = 1 (slider from 0.5 to 40, step 0.5)
F: C + (a_1 - d, 0)
B: A + (a_1 + (n * d), 0)
list1 = Sequence(A + (i / (n + 1) * (C - A)), i, 1, n)
list2 = Sequence(Element[list1, i] + (a_1 + ((i - 1) * d), 0), i, 1, n)
poly1, a, b, c, e = Polygon(A, B, F, C)
list3 = Sequence(Segment[Element[list1, j], Element[list2, j]], j, 1, n)
E = Midpoint(B, F)
α = 0 rad (slider from 0*° to 3.141592653589793, step 0.017453292519943295)
list4 = Sequence(Segment[Rotate[Element[list1, j], α, E], Rotate[Element[list2, j], α, E]], j, 1, n)
text1: " Suma \;de\; los\;" + (LaTeX[n]) + "   \space segmentos \;=\; \frac{  " + (LaTeX[n]) + "\; .\;(\; a_1\; + \;a_{" + (LaTeX[n]) + "}\;)}{ 2}  =  \frac{ " + (LaTeX[n]) + " \;. \;" + (LaTeX[(2 * a_1) + ((n - 1) * d)]) + "}{2 }  = \;" + (LaTeX[(n * ((2 * a_1) + ((n - 1) * d)) / 2)]) + ""
nada = 3.3 (slider from -5 to 5, step 0.1)
texto1: "a_{" + (LaTeX[n]) + "}=" + (LaTeX[a_1 + ((n - 1) * d)]) + ""