c

c = 7 (slider from 0.5 to 10, step 0.1)
v_a = 6 (slider from 0.5 to 10, step 0.1)
t_c = 5 (slider from 0.5 to 10, step 0.1)
A = (-4.49818181818182, -1.914710743801653)
B = Point(Circle[A, c])
text1: "1)  \text{ Zostrojíme úsečku \;  }AB=  " + (LaTeX[c]) + ""
h = Segment(A, B)