diff --git a/adafruit_gfx/gfx.py b/adafruit_gfx/gfx.py
index 745ee56..43aea04 100755
--- a/adafruit_gfx/gfx.py
+++ b/adafruit_gfx/gfx.py
@@ -25,6 +25,7 @@
 __version__ = "0.0.0+auto.0"
 __repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_GFX.git"
 
+
 # pylint: disable=invalid-name
 class GFX:
     # pylint: disable=too-many-instance-attributes
@@ -49,6 +50,7 @@ class GFX:
     :param font: An optional input to augment the default text method with a new font.
                   The input should be a properly formatted dict.
     """
+
     # pylint: disable=too-many-arguments
     def __init__(
         self,
@@ -247,7 +249,6 @@ def fill_triangle(self, x0, y0, x1, y1, x2, y2, *args, **kwargs):
             x0, x1 = x1, x0
         a = 0
         b = 0
-        y = 0
         last = 0
         if y0 == y2:
             a = x0
@@ -276,11 +277,12 @@ def fill_triangle(self, x0, y0, x1, y1, x2, y2, *args, **kwargs):
             dy12 = 1
         sa = 0
         sb = 0
-        if y1 == y2 or y0 == y1:  # pylint: disable=consider-using-in
-            last = y1
-        else:
+        y = y0
+        if y0 == y1:
             last = y1 - 1
-        for y in range(y0, last + 1):
+        else:
+            last = y1
+        while y <= last:
             a = x0 + sa // dy01
             b = x0 + sb // dy02
             sa += dx01
@@ -288,6 +290,7 @@ def fill_triangle(self, x0, y0, x1, y1, x2, y2, *args, **kwargs):
             if a > b:
                 a, b = b, a
             self.hline(a, y, b - a + 1, *args, **kwargs)
+            y += 1
         sa = dx12 * (y - y1)
         sb = dx02 * (y - y0)
         while y <= y2:
@@ -303,7 +306,8 @@ def fill_triangle(self, x0, y0, x1, y1, x2, y2, *args, **kwargs):
     def round_rect(self, x0, y0, width, height, radius, *args, **kwargs):
         """Rectangle with rounded corners drawing function.
         This works like a regular rect though! if radius = 0
-        Will draw the outline of a rectangle with rounded corners with (x0,y0) at the top left"""
+        Will draw the outline of a rectangle with rounded corners with (x0,y0) at the top left
+        """
         # shift to correct for start point location
         x0 += radius
         y0 += radius