diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
old mode 100755
new mode 100644
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 00000000..665b2882
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,10 @@
+.vs/
+out/
+build/
+cmake-build-*/
+*.ipch
+*.db
+*.log
+.DS_Store
+*.suo
+*.user
diff --git a/CMakeLists.txt b/CMakeLists.txt
old mode 100755
new mode 100644
index f83009ea..b0b0548a
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,13 +1,27 @@
-cmake_minimum_required (VERSION 3.10.2)
-project (ST-2)
+cmake_minimum_required(VERSION 3.10.2)
+project(ST-2)
 
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O3 -g")
 
-
 set(tool_dest "bin")
 set(lib_dest "lib")
 set(include_dest "include/")
 
+# Отключаем pthread на Windows
+if(WIN32)
+    set(gtest_disable_pthreads ON)
+    add_definitions(-DGTEST_HAS_PTHREAD=0)
+endif()
+
+# Подключаем Google Test
+include(FetchContent)
+FetchContent_Declare(
+    googletest
+    GIT_REPOSITORY https://github.com/google/googletest.git
+    GIT_TAG v1.14.0
+)
+FetchContent_MakeAvailable(googletest)
+
 add_subdirectory(src)
-add_subdirectory(test)
+add_subdirectory(test)
\ No newline at end of file
diff --git a/include/circle.h b/include/circle.h
index 50ac03e6..4f87713f 100644
--- a/include/circle.h
+++ b/include/circle.h
@@ -1,7 +1,23 @@
-// Copyright 2022 UNN-CS
+// Copyright 2025 UNN-CS
 #ifndef INCLUDE_CIRCLE_H_
 #define INCLUDE_CIRCLE_H_
-#include <cstdint>
 
+class Circle {
+ private:
+    double radius_;
+    double ference_;
+    double area_;
 
-#endif  // INCLUDE_CIRCLE_H_
+ public:
+    explicit Circle(double radius);
+
+    double getRadius() const;
+    double getFerence() const;
+    double getArea() const;
+
+    void setRadius(double radius);
+    void setFerence(double ference);
+    void setArea(double area);
+};
+
+#endif  // INCLUDE_CIRCLE_H_
\ No newline at end of file
diff --git a/include/tasks.h b/include/tasks.h
new file mode 100644
index 00000000..2ccb713c
--- /dev/null
+++ b/include/tasks.h
@@ -0,0 +1,9 @@
+// include/tasks.h
+#ifndef INCLUDE_TASKS_H_
+#define INCLUDE_TASKS_H_
+
+double earthRopeGap();
+double poolConcreteCost();
+double poolFenceCost();
+
+#endif  // INCLUDE_TASKS_H_
\ No newline at end of file
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
old mode 100755
new mode 100644
index e3405007..54b7a9e7
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,30 +1,33 @@
 set(header_path "${${PROJECT_NAME}_SOURCE_DIR}/include")
-set(header ${header_path}/circle.h)
-set(src circle.cpp)
+set(header 
+    ${header_path}/circle.h
+    ${header_path}/tasks.h)          # tasks.h добавлен
+set(src 
+    circle.cpp
+    tasks.cpp)                       # tasks.cpp добавлен
 
 add_library(${PROJECT_NAME} SHARED
-  ${header}
-  ${src})
+    ${header}
+    ${src})
   
 target_include_directories(${PROJECT_NAME}
-  PUBLIC ${CMAKE_CURRENT_BINARY_DIR}
-         ${${PROJECT_NAME}_SOURCE_DIR}/include)
+    PUBLIC ${CMAKE_CURRENT_BINARY_DIR}
+           ${${PROJECT_NAME}_SOURCE_DIR}/include)
 target_link_libraries(${PROJECT_NAME}
-  pthread)
+    pthread)
 
 add_executable(${PROJECT_NAME}.info main.cpp)
 target_include_directories(${PROJECT_NAME}.info
-  PUBLIC ${CMAKE_CURRENT_BINARY_DIR}
-         ${${PROJECT_NAME}_SOURCE_DIR}/include)
+    PUBLIC ${CMAKE_CURRENT_BINARY_DIR}
+           ${${PROJECT_NAME}_SOURCE_DIR}/include)
 target_link_libraries(${PROJECT_NAME}.info
-  ${PROJECT_NAME})
-
+    ${PROJECT_NAME})
 
 install(TARGETS ${PROJECT_NAME}
-        LIBRARY DESTINATION "${lib_dest}"
+    LIBRARY DESTINATION "${lib_dest}"
     ARCHIVE DESTINATION "${lib_dest}"
     COMPONENT library)
 install(TARGETS ${PROJECT_NAME}.info
-        RUNTIME DESTINATION "${tool_dest}"
+    RUNTIME DESTINATION "${tool_dest}"
     COMPONENT library)
-install(FILES ${header} DESTINATION "${include_dest}")
+install(FILES ${header} DESTINATION "${include_dest}")
\ No newline at end of file
diff --git a/src/circle.cpp b/src/circle.cpp
index 9b0d134d..4146df02 100644
--- a/src/circle.cpp
+++ b/src/circle.cpp
@@ -1,4 +1,41 @@
-// Copyright 2022 UNN-CS
-#include <cstdint>
+// Copyright 2025 UNN-CS
 #include "circle.h"
+#include <cmath>
 
+#ifndef M_PI
+#define M_PI 3.14159265358979323846
+#endif
+
+Circle::Circle(double radius) {
+    setRadius(radius);
+}
+
+double Circle::getRadius() const {
+    return radius_;
+}
+
+double Circle::getFerence() const {
+    return ference_;
+}
+
+double Circle::getArea() const {
+    return area_;
+}
+
+void Circle::setRadius(double radius) {
+    radius_ = radius;
+    ference_ = 2.0 * M_PI * radius_;
+    area_ = M_PI * radius_ * radius_;
+}
+
+void Circle::setFerence(double ference) {
+    ference_ = ference;
+    radius_ = ference_ / (2.0 * M_PI);
+    area_ = M_PI * radius_ * radius_;
+}
+
+void Circle::setArea(double area) {
+    area_ = area;
+    radius_ = std::sqrt(area_ / M_PI);
+    ference_ = 2.0 * M_PI * radius_;
+}
\ No newline at end of file
diff --git a/src/tasks.cpp b/src/tasks.cpp
new file mode 100644
index 00000000..9381c157
--- /dev/null
+++ b/src/tasks.cpp
@@ -0,0 +1,32 @@
+// src/tasks.cpp
+#include "tasks.h"
+#include "circle.h"
+#include <cmath>
+
+double earthRopeGap() {
+    const double earthRadius = 6378100.0;  // 6378.1 км в метрах
+    Circle earth(earthRadius);
+    double oldFerence = earth.getFerence();
+    earth.setFerence(oldFerence + 1.0);
+    return earth.getRadius() - earthRadius;
+}
+
+double poolConcreteCost() {
+    const double poolRadius = 3.0;
+    const double pathWidth = 1.0;
+    const double concretePrice = 1000.0;
+
+    Circle pool(poolRadius);
+    Circle outer(poolRadius + pathWidth);
+    double pathArea = outer.getArea() - pool.getArea();
+    return pathArea * concretePrice;
+}
+
+double poolFenceCost() {
+    const double poolRadius = 3.0;
+    const double pathWidth = 1.0;
+    const double fencePrice = 2000.0;
+
+    Circle outer(poolRadius + pathWidth);
+    return outer.getFerence() * fencePrice;
+}
\ No newline at end of file
diff --git a/test/AllTests.cpp b/test/AllTests.cpp
old mode 100755
new mode 100644
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
old mode 100755
new mode 100644
index 1bbc8537..ee9f667a
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -1,10 +1,14 @@
 add_executable(${PROJECT_NAME}.test
-  AllTests.cpp
-  tests.cpp)
+    tests.cpp)
+
 target_link_libraries(${PROJECT_NAME}.test
-  ${PROJECT_NAME} gtest pthread)
+    ${PROJECT_NAME}
+    gtest_main)
+
 target_compile_definitions(${PROJECT_NAME}.test 
-  PRIVATE TEST_DIR="${CMAKE_CURRENT_LIST_DIR}/test")
+    PRIVATE TEST_DIR="${CMAKE_CURRENT_LIST_DIR}")
+
+add_test(NAME ${PROJECT_NAME}_tests COMMAND ${PROJECT_NAME}.test)
 
 install(TARGETS ${PROJECT_NAME}.test
-        DESTINATION "${tool_dest}")
+    RUNTIME DESTINATION "${tool_dest}")
\ No newline at end of file
diff --git a/test/tests.cpp b/test/tests.cpp
index fc3f9336..f397d0d3 100644
--- a/test/tests.cpp
+++ b/test/tests.cpp
@@ -1,7 +1,195 @@
-// Copyright 2025 UNN-CS Team
 
+
+// Copyright 2025 UNN-CS
 #include <gtest/gtest.h>
-#include <cstdint>
 #include "circle.h"
+#include "tasks.h"
+#include <cmath>
+
+#ifndef M_PI
+#define M_PI 3.14159265358979323846
+#endif
+
+// ------------------ Тесты класса Circle ------------------
+
+TEST(CircleTest, ConstructorAndGetters) {
+    Circle c(5.0);
+    EXPECT_DOUBLE_EQ(c.getRadius(), 5.0);
+    EXPECT_DOUBLE_EQ(c.getFerence(), 2.0 * M_PI * 5.0);
+    EXPECT_DOUBLE_EQ(c.getArea(), M_PI * 25.0);
+}
+
+TEST(CircleTest, SetRadiusUpdatesFerenceAndArea) {
+    Circle c(1.0);
+    c.setRadius(3.0);
+    EXPECT_DOUBLE_EQ(c.getRadius(), 3.0);
+    EXPECT_DOUBLE_EQ(c.getFerence(), 2.0 * M_PI * 3.0);
+    EXPECT_DOUBLE_EQ(c.getArea(), M_PI * 9.0);
+}
+
+TEST(CircleTest, SetFerenceUpdatesRadiusAndArea) {
+    Circle c(1.0);
+    double newFerence = 4.0 * M_PI;
+    c.setFerence(newFerence);
+    EXPECT_DOUBLE_EQ(c.getFerence(), newFerence);
+    EXPECT_DOUBLE_EQ(c.getRadius(), 2.0);      // L=4? ? R=2
+    EXPECT_DOUBLE_EQ(c.getArea(), M_PI * 4.0);
+}
+
+TEST(CircleTest, SetAreaUpdatesRadiusAndFerence) {
+    Circle c(1.0);
+    double newArea = 9.0 * M_PI;
+    c.setArea(newArea);
+    EXPECT_DOUBLE_EQ(c.getArea(), newArea);
+    EXPECT_DOUBLE_EQ(c.getRadius(), 3.0);      // A=9? ? R=3
+    EXPECT_DOUBLE_EQ(c.getFerence(), 2.0 * M_PI * 3.0);
+}
+
+TEST(CircleTest, ZeroRadius) {
+    Circle c(0.0);
+    EXPECT_DOUBLE_EQ(c.getRadius(), 0.0);
+    EXPECT_DOUBLE_EQ(c.getFerence(), 0.0);
+    EXPECT_DOUBLE_EQ(c.getArea(), 0.0);
+}
+
+TEST(CircleTest, SetRadiusZero) {
+    Circle c(5.0);
+    c.setRadius(0.0);
+    EXPECT_DOUBLE_EQ(c.getRadius(), 0.0);
+    EXPECT_DOUBLE_EQ(c.getFerence(), 0.0);
+    EXPECT_DOUBLE_EQ(c.getArea(), 0.0);
+}
+
+TEST(CircleTest, SetFerenceZero) {
+    Circle c(5.0);
+    c.setFerence(0.0);
+    EXPECT_DOUBLE_EQ(c.getFerence(), 0.0);
+    EXPECT_DOUBLE_EQ(c.getRadius(), 0.0);
+    EXPECT_DOUBLE_EQ(c.getArea(), 0.0);
+}
+
+TEST(CircleTest, SetAreaZero) {
+    Circle c(5.0);
+    c.setArea(0.0);
+    EXPECT_DOUBLE_EQ(c.getArea(), 0.0);
+    EXPECT_DOUBLE_EQ(c.getRadius(), 0.0);
+    EXPECT_DOUBLE_EQ(c.getFerence(), 0.0);
+}
+
+TEST(CircleTest, ChainedSetRadius) {
+    Circle c(2.0);
+    c.setRadius(4.0);
+    EXPECT_DOUBLE_EQ(c.getRadius(), 4.0);
+    c.setRadius(1.0);
+    EXPECT_DOUBLE_EQ(c.getRadius(), 1.0);
+    EXPECT_DOUBLE_EQ(c.getFerence(), 2.0 * M_PI);
+    EXPECT_DOUBLE_EQ(c.getArea(), M_PI);
+}
+
+TEST(CircleTest, ChainedSetFerence) {
+    Circle c(1.0);
+    c.setFerence(2.0 * M_PI);  // R=1
+    EXPECT_DOUBLE_EQ(c.getRadius(), 1.0);
+    c.setFerence(4.0 * M_PI);  // R=2
+    EXPECT_DOUBLE_EQ(c.getRadius(), 2.0);
+    EXPECT_DOUBLE_EQ(c.getArea(), M_PI * 4.0);
+}
+
+TEST(CircleTest, ChainedSetArea) {
+    Circle c(1.0);
+    c.setArea(M_PI);           // R=1
+    EXPECT_DOUBLE_EQ(c.getRadius(), 1.0);
+    c.setArea(4.0 * M_PI);     // R=2
+    EXPECT_DOUBLE_EQ(c.getRadius(), 2.0);
+    EXPECT_DOUBLE_EQ(c.getFerence(), 4.0 * M_PI);
+}
+
+TEST(CircleTest, Precision) {
+    Circle c(1.0);
+    c.setRadius(1.0/3.0);
+    double expectedRadius = 1.0/3.0;
+    EXPECT_NEAR(c.getRadius(), expectedRadius, 1e-12);
+    EXPECT_NEAR(c.getFerence(), 2.0 * M_PI * expectedRadius, 1e-12);
+    EXPECT_NEAR(c.getArea(), M_PI * expectedRadius * expectedRadius, 1e-12);
+}
+
+// ------------------ Тесты задачи "Земля и верёвка" ------------------
+
+TEST(EarthRopeTest, GapPositive) {
+    double gap = earthRopeGap();
+    EXPECT_GT(gap, 0.0);
+    // Теоретически зазор = 1/(2?) ? 0.159 м
+    EXPECT_NEAR(gap, 1.0 / (2.0 * M_PI), 1e-9);
+}
+
+TEST(EarthRopeTest, GapIndependentOfRadius) {
+    // Проверим, что зазор не зависит от начального радиуса (математически)
+    double gap = earthRopeGap();
+    // Создадим круг с другим радиусом и повторим логику вручную
+    double testRadius = 1000.0;
+    Circle testCircle(testRadius);
+    double oldL = testCircle.getFerence();
+    testCircle.setFerence(oldL + 1.0);
+    double newR = testCircle.getRadius();
+    double manualGap = newR - testRadius;
+    EXPECT_NEAR(gap, manualGap, 1e-9);
+}
+
+// ------------------ Тесты задачи "Бассейн" ------------------
+
+TEST(PoolTest, ConcreteCostPositive) {
+    double cost = poolConcreteCost();
+    EXPECT_GT(cost, 0.0);
+    // Площадь дорожки: ?*(4^2 - 3^2) = ?*7 ? 21.991, стоимость ? 21991
+    double expectedArea = M_PI * (16.0 - 9.0); // 7?
+    double expectedCost = expectedArea * 1000.0;
+    EXPECT_NEAR(cost, expectedCost, 1e-6);
+}
+
+TEST(PoolTest, FenceCostPositive) {
+    double cost = poolFenceCost();
+    EXPECT_GT(cost, 0.0);
+    // Длина ограды: 2?*4 = 8? ? 25.133, стоимость ? 50265.48
+    double expectedLength = 2.0 * M_PI * 4.0;
+    double expectedCost = expectedLength * 2000.0;
+    EXPECT_NEAR(cost, expectedCost, 1e-6);
+}
+
+TEST(PoolTest, ConcreteCostExact) {
+    double cost = poolConcreteCost();
+    // Точное значение: 1000 * ? * (4^2 - 3^2) = 1000 * ? * 7 = 7000?
+    double exact = 7000.0 * M_PI;
+    EXPECT_NEAR(cost, exact, 1e-6);
+}
+
+TEST(PoolTest, FenceCostExact) {
+    double cost = poolFenceCost();
+    // Точное значение: 2000 * 2?*4 = 2000 * 8? = 16000?
+    double exact = 16000.0 * M_PI;
+    EXPECT_NEAR(cost, exact, 1e-6);
+}
+
+// Дополнительные тесты для проверки независимости вычислений
+TEST(PoolTest, ConcreteVsManual) {
+    double r_inner = 3.0;
+    double r_outer = 4.0;
+    double areaPath = M_PI * (r_outer*r_outer - r_inner*r_inner);
+    double expected = areaPath * 1000.0;
+    EXPECT_DOUBLE_EQ(poolConcreteCost(), expected);
+}
 
+TEST(PoolTest, FenceVsManual) {
+    double r_outer = 4.0;
+    double length = 2.0 * M_PI * r_outer;
+    double expected = length * 2000.0;
+    EXPECT_DOUBLE_EQ(poolFenceCost(), expected);
+}
 
+// Проверка на использование класса Circle в задачах (косвенно)
+TEST(PoolTest, CircleUsage) {
+    Circle pool(3.0);
+    Circle outer(4.0);
+    double pathArea = outer.getArea() - pool.getArea();
+    double concreteCost = pathArea * 1000.0;
+    EXPECT_DOUBLE_EQ(concreteCost, poolConcreteCost());
+}
\ No newline at end of file