If spongebob's house is round from outside, then why does the inside have corners?

 If spongebob lives in a round pineapple why r there corners in his house? He can have a pineapple with corners as a house. ... Spongebob's house looks small on the outside, but it's like a mansion on the inside! Please upload a file larger than 100x100 pixels; We are experiencing some problems, ... 124 Conch Street is the address of the pineapple house where SpongeBob ... the episode "The Gift of Gum" when SpongeBob tried to sneak Gummy outside. a porthole window from which the inside of Squidward's House can be seen. The interior of SpongeBob's house has corners even though the exterior is round.