Here is my full code :s

#define _USE_MATH_DEFINES

#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <math.h>

void drawCircle(GLfloat x, GLfloat y, GLfloat z, GLfloat radius, GLint numberOfSides);

int main(void)
{
    GLFWwindow *window;

    if (!glfwInit())
    {
        return -1;
    }

    window = glfwCreateWindow(512, 512, "OpenGL Test", NULL, NULL);

    if (!window)
    {
        glfwTerminate();
        return -1;
    }

    while (!glfwWindowShouldClose(window))
    {
        glClear(GL_COLOR_BUFFER_BIT);

        glfwSwapBuffers(window);

        glfwPollEvents();
    }

    glfwTerminate();
}

void drawCircle(GLfloat x, GLfloat y, GLfloat z, GLfloat radius, GLint numberOfSides)
{
    const GLint numberOfVertices = numberOfSides + 2;

    GLfloat doublePi = 2.0f * M_PI;

    GLfloat circleVerticesX[numberOfVertices];
    GLfloat circleVerticesY[numberOfVertices];
    GLfloat circleVerticesZ[numberOfVertices];
}

My problem is at

GLfloat circleVerticesX[numberOfVertices];
GLfloat circleVerticesY[numberOfVertices];
GLfloat circleVerticesZ[numberOfVertices];

numberOfVertices gives me the error

Thank you!