Assume that the Simpson's really were 2D creatures living in an x-y plane and that Homer and Bart had made the transformation to 3D creatures. While a 2D Marge can't really understand the 3rd dimension and would feel like there isn't any room for another dimension, she could see weird behavior occurring that suggests that the 3rd dimension exists (for example the "wall" that Homer disappeared into). 2D Marge wouldn't be able to comprehend the concept of depth or an entire 3D Homer, since only 2D pieces would make sense to her.
Write a letter from 3D Homer Simpson to his 2D wife Marge which discusses his and Bart's change from 2D into 3D. Be sure to include mathematical explanations in addition to physical descriptions. Compare and contrast Homer and Bart's 2D and 3D appearances.
Go through these links FROM INTERNET EXPLORER and use the information contained within them to help you in your writeup.
Pictures of Homer Changing into 3-d and 3-d Homer.
Text transcript of 3-d Homer segment and Did You Notice? by James A. Cherry
Text of Pacific Data Images description of the 3-d special
Text of How did Pacific Data Images do this?