Waves on a blender

Hey there, As part of a school assignment we are asked to make a blender. How would I go about making the bottom wavy part of the nutribullet? I have been struggling to make it over the last few weeks. If someone could point me in the right direction it would be much appreciated!

Thanks

.http://www.originalnutribullet.com.au/assets/Uploads/products/NutriBullet600-Power-Base.jpg

SolidworksParts And Features