How many dimensions are there according to Buddhism? Humans or most of the organisms in this world can perceive three dimensions. Does buddhism explain about dimensions? If so how many are there?
The Sigalovada Sutta mention "the six directions":


  At that time a young householder named Sigalaka arose early and set out from Rajagaha with freshly washed clothes and hair.[3] With palms together held up in reverence,[4] he was paying respect towards the six directions:[5] that is east, south, west, north, lower and upper.


I take that to imply three dimensions.

It's not explicitly about dimensions but it casually implies in passing that there are three dimensions (perhaps as if it's the kind of thing that everyone knows and doesn't need explaining).

Modern maths (since the late 18th century) has described "time" as a kind of dimension. Buddhist texts imply that time, too, can be perceived.