In this article, we will learn the types of diagonals in a cube , the diagonal of a cube formula, the derivation of the diagonal of a cube formula, and problems based on it. The formula of Diagonal of Cube and its derivation, Properties of Cube and example questions. We also have to check the face diagonal and body diagonal of a cube . This article encompasses all about it! The main diagonal of a cube is the one that cuts through the centre of the cube; the diagonal of a face of a cube is not the main diagonal. The main diagonal of any cube can be found by multiplying the length of one side by the square root of 3. Learn how to find the diagonal of a cube using the formula d = 3a, where a is the side length. See examples, properties, and differences between cube and cuboid.