def write_signed_area(self):
    words = TextMobject("``Signed area''")
    words.next_to(self.coords_to_point(self.sample_input, 0), UP)
    symbols = VGroup(*[TexMobject(sym).move_to(self.coords_to_point(*coords)) for (sym, coords) in [('+', (1, 2)), ('-', (5, (- 1))), ('+', (7.6, 0.5))]])
    self.play(Write(words))
    self.play(Write(symbols))
    self.wait()
def write_signed_area(self):
    words = TextMobject("``Signed area")
    words.next_to(self.coords_to_point(self.sample_input, 0), UP)
    symbols = VGroup(*[TexMobject(sym).move_to(self.coords_to_point(*coords)) for (sym, coords) in [('+', (1, 2)), ('-', (5, (- 1))), ('+', (7.6, 0.5))]])
    self.play(Write(words))
    self.play(Write(symbols))
    self.wait()