Ubuntu 20.04 OpenGL error: /usr/bin/ld: cannot find -lG

I'm trying to follow this tutorial from 2018:

http://www.codebind.com/linux-tutorials/install-opengl-ubuntu-linux/

I'm under the impression that things must have changed with Ubuntu and configuring OpenGL since these instructions no longer work. In case the article disappears at some point I'll re-iterate all the steps here:

Ubuntu 20.04 install

Verify NVIDIA GPU is properly recognized by Ubuntu, install and configure CUDA (verified works with PyTorch)

Now on to the OpenGL specific stuff:

sudo apt-get install libglu1-mesa-dev freeglut3-dev mesa-common-dev

enter this program in gedit, save it as main.cpp:

#include <GL/glut.h>

void displayMe(void)
{
    glClear(GL_COLOR_BUFFER_BIT);
    glBegin(GL_POLYGON);
    glVertex3f(0.5, 0.0, 0.5);
    glVertex3f(0.5, 0.0, 0.0);
    glVertex3f(0.0, 0.5, 0.0);
    glVertex3f(0.0, 0.0, 0.5);
    glEnd();
    glFlush();
}

int main(int argc, char** argv)
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_SINGLE);
    glutInitWindowSize(400, 300);
    glutInitWindowPosition(100, 100);
    glutCreateWindow("Hello world!");
    glutDisplayFunc(displayMe);
    glutMainLoop();
    return 0;
}

Compile:

gcc main.cpp -o firstOpenGlApp -lglut -lGLU -lG

Here is the resulting output:

$ gcc main.cpp -o firstOpenGlApp -lglut -lGLU -lG
/usr/bin/ld: cannot find -lG
collect2: error: ld returned 1 exit status

Did something pertaining to configuring OpenGL change since this tutorial was written? What am I missing?