Well,... isn't a perfect sphere...
[nasa.gov]earth-58.html
Even though our planet is a sphere, it is not a perfect sphere. Because of the force caused when Earth rotates, the North and South Poles are slightly flat. Earth's rotation, wobbly motion and other forces are making the planet change shape very slowly, but it is still round.
Posted by GuyIncognitoWhat shape do you think the earth is?
Posted by GuyIncognitoWelcome to the Flat Earth group! Here you may discuss the flat earth theory, as well as the other alternative earth shape theories (cone, cube, doughnut etc).