2D and 3D shapes in the world
Maths · Early Years · The School
Flat and solid
A FLAT shape, like a circle or a square, sits on a page. You could trace all the way round it with one finger, on one surface. A SOLID shape, like a ball or a box, takes up real space. You have to pick it up and turn it to see all of it. Flat shapes are called 2D. Solid shapes are called 3D.
Naming solid shapes
A dice is a CUBE — six flat square faces. A ball is a SPHERE — round all over, no faces at all. A party hat is a CONE — a point at the top, a circle at the bottom. A tin of beans is a CYLINDER — two flat circles, joined by a curved side. Find one of each around your home.
Flat faces on solid shapes
Many solid shapes have FLAT FACES hiding on them. A cube has six flat square faces — trace round one with your finger, and you have traced a square. A cylinder has two flat circular faces, top and bottom. Finding the flat shape inside a solid one connects the two ideas together.
Pick up a tin can. Look at the whole tin: it is a CYLINDER, a solid, 3D shape. Now look at just the top of it. Trace round the top edge with your finger. That flat top is a CIRCLE, a 2D shape. The bottom is a circle too. The curved side that wraps around is neither flat nor a face you can trace in one go. One solid object, and two flat circles hiding on it, top and bottom.