diff --git a/helix/presenters/panel_presenter.py b/helix/presenters/panel_presenter.py
index f36841e..7cee812 100644
--- a/helix/presenters/panel_presenter.py
+++ b/helix/presenters/panel_presenter.py
@@ -88,9 +88,8 @@ class ProjectPresenter(object):
                 corner_length = sqrt((next_corner[0] - corner[0])**2 + (next_corner[1] - corner[1])**2)
                 k1 = (corner[1] - previous_corner[1]) / (corner[0] - previous_corner[0])
                 k2 = (next_corner[1] - corner[1]) / (next_corner[0] - corner[0])
-                theta1 = degrees(atan(k1))
                 theta2 = degrees(atan(k2))
-                theta1 = theta1 - theta2
+                theta1 = degrees(atan(k1)) - theta2
                 if (theta1 < 0):
                     if (k1 < 0 and k2 < 0):
                         theta1 = 360 + theta1