3D shapes are shapes that have 3 dimensions (height, length and depth)
Some vocab you need to know:
- Face(s): face or faces are the “sides” of a 3D shape, for example: a cube has 6 faces.
- Edge(s): edge or edges are the lines between a face and another or the lines that connect an vertex by another.
- Vertex (Pl: vertices): a vertex is a corner between 2 edges (lines).
- Volume: volume is the amount that we can feel inside the shape, (the space inside the shape).
- Apex(es): the highest point.
What is the difference between 3D and 2D shapes?
3D shapes have got 3-dimensions (height, depth and length) but 2D have shapes got 2 dimensions only (widthand height).
Basically, that means 3D shapes are shapes that we can put something inside of, but 2D shapes are flat shapes so we can’t put some thing inside them, however we can put something on them (like we can fill a square by a colour on a paper).
Here are some basic 3D-shapes:
This 3D shape is a cube, it has 6 squared faces, 12 edges and 8 vertices.
A cube is a 3D object from the square.
To workout the volume of a cube we can multiply the height by the width by the depth.
V= Height ˣ Width ˣ Depth
This shape is a cylinder, it has 3 faces (2-circular and 1-rectangle) and 2 edges
The bottom circular face is called “the base”
A cylinder is the a 3D object from a circle.
To work out the volume of a cylinder you can use this formula :
V =π r2 h
This 3d shape is a cuboid, it has 6-faces, 8-edges and 8 vertices.
A cuboid is a 3D object made from rectangles.
To calculate the volume of a cuboid we multiply the height by the length by the depth. V = Height ˣ Length ˣ Depth
This 3d Shape is a cone, It has 2 faces and one apex.
The bottom face called “the base“.
To workout the volume of a cone : V = π R3 H/3
This 3d Shape is a squared based pyramid, it has 5 faces (1 squared base and 4 triangular faces). It has one apex.
To workout the volume of a square based pyramid: V = LW h/3
L = length W=width H=height