opengl draw cresent moon c++

#include <GL/glut.h>
#include <cmath>

void drawCrescentMoon() {
    glClear(GL_COLOR_BUFFER_BIT);

    glBegin(GL_POLYGON);

    for (int i = 0; i < 360; i++) {
        float angle = i * M_PI / 180.0;
        float x = 0.2 * cos(angle);
        float y = 0.2 * sin(angle);
        glVertex2f(x + 0.5, y + 0.5);
    }

    glEnd();

    glBegin(GL_POLYGON);

    for (int i = 0; i < 360; i++) {
        float angle = i * M_PI / 180.0;
        float x = 0.15 * cos(angle);
        float y = 0.15 * sin(angle);
        glVertex2f(x + 0.65, y + 0.5);
    }

    glEnd();

    glFlush();
}

void display() {
    glClearColor(0.0, 0.0, 0.0, 1.0);
    glColor3f(1.0, 1.0, 1.0);

    glLoadIdentity();
    gluOrtho2D(0.0, 1.0, 0.0, 1.0);

    drawCrescentMoon();
}

int main(int argc, char argv) {
    glutInit(&argc, argv);
    glutCreateWindow("Crescent Moon");
    glutInitWindowSize(500, 500);
    glutDisplayFunc(display);

    glutMainLoop();

    return 0;
}