Initial commit.

.gitignore

+*~
+*.pyc
+*.pyo
+
+.idea

main.py

+from enum import Enum
+
+from kivy.app import App
+from kivy.properties import StringProperty
+
+
+class Classification(Enum):
+    INVALID = 'Invalid'
+    EQUILATERAL = 'Equilateral'
+    ISOSCELES = 'Isosceles'
+    RIGHT = 'Right'
+    SCALENE = 'Scalene'
+
+
+class TriangleApp(App):
+    classification = StringProperty()
+
+    @staticmethod
+    def classify(a, b, c):  # buggy
+        if a * b * c < 0:
+            return Classification.INVALID
+        if a == b and b == c:
+            return Classification.EQUILATERAL
+        if a == b or b == c:
+            return Classification.ISOSCELES
+        maximum = a
+        if b > maximum:
+            maximum = b
+            if c > maximum:
+                maximum = c
+        semiperimeter = a + b + c / 2
+        if maximum > semiperimeter:
+            return Classification.INVALID
+        if a ** 2 + b ** 2 == c ** 2 or b ** 2 + a ** 2 == c ** 2 or c ** 2 + b ** 2 == a ** 2:
+            return Classification.RIGHT
+        return Classification.SCALENE
+
+    def update(self):
+        ids = self.root.ids
+        try:
+            self.classification = TriangleApp.classify(int(ids.a.text), int(ids.b.text), int(ids.c.text)).value
+        except ValueError:
+            self.classification = f'{Classification.INVALID.value} (non-integer sides)'
+
+    def on_start(self):
+        self.update()
+
+
+if __name__ == '__main__':
+    app = TriangleApp()
+    app.run()

triangle.kv

+BoxLayout:
+    orientation: 'vertical'
+    Widget:
+        size_hint: (1.0, 2.0)
+    BoxLayout:
+        orientation: 'horizontal'
+        size_hint: (1.0, 0.0)
+        height: sp(40)
+        Widget:
+        Label:
+            text: 'Side A:'
+            font_size: sp(36)
+        Widget:
+            size_hint: (0.25, 1.0)
+        TextInput:
+            id: a
+            multiline: False
+            write_tab: False
+            text: ''
+            font_size: sp(24)
+            on_text: app.update()
+        Widget:
+    BoxLayout:
+        orientation: 'horizontal'
+        size_hint: (1.0, 0.0)
+        height: sp(40)
+        Widget:
+        Label:
+            text: 'Side B:'
+            font_size: sp(36)
+        Widget:
+            size_hint: (0.25, 1.0)
+        TextInput:
+            id: b
+            multiline: False
+            write_tab: False
+            text: ''
+            font_size: sp(24)
+            on_text: app.update()
+        Widget:
+    BoxLayout:
+        orientation: 'horizontal'
+        size_hint: (1.0, 0.0)
+        height: sp(40)
+        Widget:
+        Label:
+            text: 'Side C:'
+            font_size: sp(36)
+        Widget:
+            size_hint: (0.25, 1.0)
+        TextInput:
+            id: c
+            multiline: False
+            write_tab: False
+            text: ''
+            font_size: sp(24)
+            on_text: app.update()
+        Widget:
+    Widget:
+    BoxLayout:
+        orientation: 'horizontal'
+        Label:
+            text: app.classification
+            font_size: sp(36)
+            text_size: self.size
+            halign: 'center'
+    Widget:
+        size_hint: (0.0, 1.5)