What are dimensions

Dimensions are plural of dimension . Dimension is measurement of length or height of one direction . Dimension is different from simple height and width .

You are heard about the words 3d and 2d . These words are use to declare engineering sizes of any product .

Dimension is only called directional length ,height and depth . Words height ,width and length represent size of any physical entity . A three sides entity can be two dimensional .

2D or 2 dimensions

Take two triangles . One triangle is draw on paper .Measurements of the triangle lines are 3 inch , 4 inch and 4 inch . This is (measurements ) sizes of triangle lines .

In the drawn triangle has only two dimensions not three . Because ,when u see the drawn triangle you can see only height and width of triangle . It has 2d or 2 dimensions .

3D or 3 dimensions

Second triangle made by cutting a 2 inch thick plastic sheet . Measurements of second triangle is also same 3 inch , 4 inch and 4 inch .

Place both triangles side by side . Know see the figure drawn on paper . You can see only two dimensions . But when you see the triangle cut with plastic piece , you can see another side . Which is depth of the triangle  .

Depth is the third dimension of any entity. You can also call this plastic triangle a 3D product . So when you see a 3d image or 3d product ,it obvious means you can see depth of the product or image .