diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
new file mode 100644
index 0000000000..125988a1d9
--- /dev/null
+++ b/.github/workflows/main.yml
@@ -0,0 +1,35 @@
+name: CI
+
+on:
+  push:
+    branches-ignore:
+      - 'main'
+      - 'lab_work_2_466894'
+      - 'lab_work_3_466894'
+      - 'lab_work_4_466894'
+  
+  workflow_dispatch:
+
+jobs:
+  test:
+    name: Run Unit Tests
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest]
+    
+    steps:
+      # parsing the code from the repository
+      - name: Checkout repository
+        uses: actions/checkout@v3
+
+      # python set-up
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: 3.11
+
+      # Running unit-tests
+      - name: Run Unit Tests
+        run: python -m unittest discover
diff --git a/circle.py b/circle.py
index c3eb8647c9..c017c319c5 100644
--- a/circle.py
+++ b/circle.py
@@ -2,9 +2,40 @@
 
 
 def area(r):
+    """
+    Принимает радиус, возвращает площадь круга
+
+    Параметр:
+        r (int): радиус
+    Возвращаемое значачение:
+        math.pi * r * r (float): площадь круга
+
+    Примеры:
+        area(3) --> 9pi
+        area(2) --> 4pi
+    """
+
+    if r <= 0:
+        raise ValueError("radius can't be negative or equal to zero")
+
     return math.pi * r * r
 
 
 def perimeter(r):
-    return 2 * math.pi * r
+    """
+    Принимает радиус, возвращает периметр круга
 
+    Параметр:
+        r (int): радиус
+    Возвращаемое значение:
+        2 * math.pi * r (float): периметр круга
+
+    Примеры:
+        perimeter(3) --> 6pi
+        perimeter(2) --> 4pi
+    """
+
+    if r <= 0:
+        raise ValueError("radius can't be  or equal to zero")
+
+    return 2 * math.pi * r
diff --git a/docs/README.md b/docs/README.md
index 63f8727939..7b0df86697 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -7,4 +7,51 @@
 ## Perimeter
 - Circle: P = 2πR
 - Rectangle: P = 2a + 2b
-- Square: P = 4a
\ No newline at end of file
+- Square: P = 4a
+---
+*Hash of the commit, which the following documentation was added in:* `[3fea8dcd2794d25b67fc722559d68d46335c3a1b](https://github.com/MurzikKrot/geometric_lib/commit/3fea8dcd2794d25b67fc722559d68d46335c3a1b)`
+# **[Сircle.py](https://github.com/MurzikKrot/geometric_lib/blob/lab_work_2_466894/circle.py) description**
+This file contains 2 functions `area` and `perimeter`.
+## **area**
+This function calculates an area of a circle of given radius.
+### Parameters
+**`r`** - radius of the circle of type `int` .
+### Return Value
+Area of the circle of type `float`.
+### Examples
+\(pi rounded to 3,14)
+- `area(5)` -->  `78,5`
+- `area(6)` -->  `113,04`
+
+## **perimeter**
+This function calculates a perimeter of a circle of given radius.
+### Parameters
+**`r`** - radius of the circle of type `int` .
+### Return Value
+Perimeter of the circle of type `float`.
+### Examples
+\(pi rounded to 3,14)
+- `perimeter(5)` -->  `31,4`
+- `perimeter(6)` -->  `37,68`
+---
+# **[Square.py](https://github.com/MurzikKrot/geometric_lib/blob/lab_work_2_466894/square.py) description**
+This file contains 2 functions `area` and `perimeter`.
+## **area**
+This function calculates an area of a square of given length of a side.
+### Parameters
+**`a`** - length of a side of the square of type `int` .
+### Return Value
+Area of the square of tupe `int`.
+### Examples
+- `area(5)` -->  `25`
+- `area(6)` -->  `36`
+
+## **perimeter**
+This function calculates a perimeter of a square of given length of a side.
+### Parameters
+**`a`** - length of a side of the square of type `int` .
+### Return Value
+Perimeter of the square of tнpe `int`.
+### Examples
+- `perimeter(5)` -->  `20`
+- `perimeter(6)` -->  `24`
\ No newline at end of file
diff --git a/rectangle.py b/rectangle.py
new file mode 100644
index 0000000000..d9e7073e86
--- /dev/null
+++ b/rectangle.py
@@ -0,0 +1,44 @@
+def area(a, b):
+    """
+    Принимает длину и ширину, возвращает площадь прямоугольника
+
+    Параметры:
+        a (int): длина
+        h (int): ширина
+    Возвращаемое значачение:
+        a * h (int): площадь прямоугольника
+
+    Примеры:
+        area(3, 5) --> 15
+        area(1, 2) --> 2
+    """
+
+    if a <= 0:
+        raise ValueError("length can't be negative or equal to zero")
+    elif b <= 0:
+        raise ValueError("width can't be negative or equal to zero")
+
+    return a * b
+
+
+def perimeter(a, b):
+    """
+    Принимает длину и ширину, возвращает периметр прямоугольника
+
+    Параметры:
+        a (int): длина
+        h (int): ширина
+    Возвращаемое значачение:
+        (a + h)*2 (int): периметр прямоугольника
+
+    Примеры:
+        perimeter(3, 5) --> 16
+        perimeter(1, 2) --> 6
+    """
+
+    if a <= 0:
+        raise ValueError("length can't be negative or equal to zero")
+    elif b <= 0:
+        raise ValueError("width can't be negative or equal to zero")
+
+    return (a + b)*2
diff --git a/square.py b/square.py
index 0f98724205..5bcc62a0f4 100644
--- a/square.py
+++ b/square.py
@@ -1,7 +1,39 @@
 
 def area(a):
+    """
+    Принимает длину стороны квадрата, возвращает его площадь
+
+    Параметр:
+        a (int): длина стороны квадрата
+    Возвращаемое значение:
+        a * a (int): площадь квадрата
+
+    Примеры:
+        area(3) --> 9
+        area(2) --> 4
+    """
+
+    if a <= 0:
+        raise ValueError("length can't be negative or equal to zero")
+
     return a * a
 
 
 def perimeter(a):
+    """
+    Принимает длину стороны квадрата, возвращает его периметр
+
+    Параметр:
+        a (int): длина стороны квадрата
+    Возвращаемое значение:
+        4 * a (int): периметр квадрата
+
+    Примеры:
+        perimeter(3) --> 12
+        perimeter(2) --> 8
+    """
+
+    if a <= 0:
+        raise ValueError("length can't be negative or equal to zero")
+
     return 4 * a
diff --git a/testCircle.py b/testCircle.py
new file mode 100644
index 0000000000..6301f5e084
--- /dev/null
+++ b/testCircle.py
@@ -0,0 +1,20 @@
+import unittest
+import circle
+
+
+class TestCircle(unittest.TestCase):
+    def test_area(self):
+        self.assertAlmostEqual(circle.area(3), 28.274, 3)
+        self.assertAlmostEqual(circle.area(2), 12.566, 3)
+
+        self.assertRaises(ValueError, circle.area, -5)
+
+    def test_perimeter(self):
+        self.assertAlmostEqual(circle.perimeter(3), 18.850, 3)
+        self.assertAlmostEqual(circle.perimeter(2), 12.566, 3)
+
+        self.assertRaises(ValueError, circle.perimeter, -5)
+
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/testRectangle.py b/testRectangle.py
new file mode 100644
index 0000000000..38a25e4ed3
--- /dev/null
+++ b/testRectangle.py
@@ -0,0 +1,24 @@
+import unittest
+import rectangle
+
+
+class TestRectangle(unittest.TestCase):
+    def test_area(self):
+        self.assertEqual(rectangle.area(3, 5), 15)
+        self.assertEqual(rectangle.area(1, 2), 2)
+
+        self.assertRaises(ValueError, rectangle.area, -5, 1)
+        self.assertRaises(ValueError, rectangle.area, 5, -1)
+        self.assertRaises(ValueError, rectangle.area, -5, -1)
+
+    def test_perimeter(self):
+        self.assertEqual(rectangle.perimeter(3, 5), 16)
+        self.assertEqual(rectangle.perimeter(1, 2), 6)
+
+        self.assertRaises(ValueError, rectangle.perimeter, -5, 1)
+        self.assertRaises(ValueError, rectangle.perimeter, 5, -1)
+        self.assertRaises(ValueError, rectangle.perimeter, -5, -1)
+
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/testSquare.py b/testSquare.py
new file mode 100644
index 0000000000..20e0d74a4d
--- /dev/null
+++ b/testSquare.py
@@ -0,0 +1,20 @@
+import unittest
+import square
+
+
+class Testsquare(unittest.TestCase):
+    def test_area(self):
+        self.assertEqual(square.area(3), 9)
+        self.assertEqual(square.area(2), 4)
+
+        self.assertRaises(ValueError, square.area, -5)
+
+    def test_perimeter(self):
+        self.assertEqual(square.perimeter(3), 12)
+        self.assertEqual(square.perimeter(2), 8)
+
+        self.assertRaises(ValueError, square.perimeter, -5)
+
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/testTriangle.py b/testTriangle.py
new file mode 100644
index 0000000000..c5f22b18c7
--- /dev/null
+++ b/testTriangle.py
@@ -0,0 +1,24 @@
+import unittest
+import triangle
+
+
+class TestTriangle(unittest.TestCase):
+    def test_area(self):
+        self.assertEqual(triangle.area(3, 5), 7.5)
+        self.assertEqual(triangle.area(1, 2), 1.0)
+
+        self.assertRaises(ValueError, triangle.area, -5, 1)
+        self.assertRaises(ValueError, triangle.area, 5, -1)
+        self.assertRaises(ValueError, triangle.area, -5, -1)
+
+    def test_perimeter(self):
+        self.assertEqual(triangle.perimeter(3, 5, 6), 14)
+        self.assertEqual(triangle.perimeter(1, 2, 3), 6)
+
+        self.assertRaises(ValueError, triangle.perimeter, -5, 1, 3)
+        self.assertRaises(ValueError, triangle.perimeter, 5, -1, 3)
+        self.assertRaises(ValueError, triangle.perimeter, -5, -1, -3)
+
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/triangle.py b/triangle.py
new file mode 100644
index 0000000000..3d36b18c33
--- /dev/null
+++ b/triangle.py
@@ -0,0 +1,47 @@
+def area(a: int, h: int):
+    """
+    Принимает длину основания и высоту, возвращает площадь треугольника
+
+    Параметры:
+        a (int): длина основания
+        h (int): высота
+    Возвращаемое значение:
+        a * h / 2 (float): площадь треугольника
+
+    Примеры:
+        area(3, 5) --> 7.5
+        area(1, 2) --> 1.0
+    """
+
+    if a <= 0:
+        raise ValueError("length can't be negative or equal to zero")
+    elif h <= 0:
+        raise ValueError("height can't be negative or equal to zero")
+
+    return a * h / 2
+
+
+def perimeter(a, b, c):
+    """
+    Принимает длины 3-х сторон, возвращает периметр треугольника
+
+    Параметры:
+        a (int): длина 1 стороны
+        b (int): длина 2 стороны
+        c (int): длина 3 стороны
+    Возвращаемое значение:
+        a + b + c (int): периметр треугольника
+
+    Примеры:
+        perimeter(3, 5, 6) --> 14
+        perimeter(1, 2, 3) --> 6
+    """
+
+    if a <= 0:
+        raise ValueError("length can't be negative or equal to zero")
+    elif b <= 0:
+        raise ValueError("length can't be negative or equal to zero")
+    elif c <= 0:
+        raise ValueError("length can't be negative or equal to zero")
+
+    return a + b + c