Is it a rectangle? Is it a plane? No…it’s a square?!11 Optical Illusions Found in Visual Design21K24Balraj ChanaNancy PongNov 23, 2017·1 min readHi, Balraj Chana! As promised, I’m translating your article :) I do have a couple of questions. What do you mean by “plane” here? Like from math — a surface that goes in all directions?