The experience of visualizing the corner triangles folding over can lead one to this belief. But it cannot provide good evidence for it. This is because visual experience (of sight or imagination) has limited acuity and so does not enable us to discriminate between a situation in which the outer triangles fit the inner square exactly and a situation in which they fit inexactly but well enough for the mismatch to escape visual detection. (This contrasts with the case of discovering the number of vertices of a cube by seeing or visualizing one.) Even though visualizing the square, the inner square and then visualizing the corner triangles folding over is constrained by the results of earlier perceptual experience of scenes with relevant similarities, we cannot draw from it reliable information about exact equality of areas, because perception itself is not reliable about exact equalities (or exact proportions) of continuous magnitudes.