Visual intuition fails when you have more than 3 dimensions or 4 in some cases. I can visualise a right angle in 2 and 3 dimensions. In 4 dimensions I can't v

Visual intuition fails when you have more than 3 dimensions or 4 in some cases. I can visualise a right angle in 2 and 3 dimensions. In 4 dimensions I can't visualise it and the whole idea of an angle no longer seems to make sense. And yet I still need to use this notion of a right angle in more than 3 dimensions in order to reason about certain problems.