Ffigurau
Ffigur 1: © Agelika Schwarz/iStockphoto.com; © Elena Ellisseeva/iStockphoto.com
Ffigur 2: © Y Brifysgol Agored
Ffigur 3: © Y Brifysgol Agored
Ffigur 4: © ddim yn hysbys
Ffigur 5: O'r chwith i'r dde: © PeopleImages/iStockphoto.com, Shapecharge/iStockphoto.com, ImagePhotography/iStockphoto.com, Sebra 1/iStockphoto.com
Ffigur 6: © Y Brifysgol Agored
Ffigur 7: © Y Brifysgol Agored
Ffigur 8: © Y Brifysgol Agored