Geometry

Geometry is all about shapes and their properties.

If you like playing with objects, or like drawing, then geometry is for you!

Geometry can be divided into:

plane Plane Geometry is about flat shapes like lines, circles and triangles ... shapes that can be drawn on a piece of paper
   
Solid Geometry is about three dimensional objects like cubes, prisms, cylinders and spheres.

Hint: Try drawing some of the shapes and angles as you learn ... it helps.

 

dimensions

Point, Line, Plane and Solid

A Point has no dimensions, only position
A Line is one-dimensional
A Plane is two dimensional (2D)
A Solid is three-dimensional (3D)

Plane Geometry

Plane Geometry is all about shapes on a flat surface (like on an endless piece of paper).

 




Polygons

A Polygon is a 2-dimensional shape made of straight lines. Triangles and Rectangles are polygons.

Here are some more:

Pentagon Pentagon
Pentagram Pentagram
Hexagon Hexagon

 

 

The Circle

Circle Theorems (Advanced Topic)

 

Symbols

There are many special symbols used in Geometry. Here is a short reference for you:

Geometric Symbols

 

Congruent and Similar

 

Angles

angles
Types of Angles

 

Compass  

Using Drafting Tools

 

Transformations and Symmetry

Transformations:

symmetry drawing

Symmetry:



 

Coordinates

interactive-cartesian-coordinates

 

 

More Advanced Topics in Plane Geometry

Pythagoras

abc triangle

 

Conic Sections

 

Trigonometry

Right-Angled Triangle

Trigonometry is a special subject of its own, so you might like to visit:

 

Solid Geometry

Solid Geometry is the geometry of three-dimensional space - the kind of space we live in ...

... let us start with some of the simplest shapes:


Common 3D Shapes

Polyhedra and Non-Polyhedra

There are two main types of solids, "Polyhedra", and "Non-Polyhedra":

Polyhedra :
(they must have flat faces)
hexahedron square prism Cubes and
Cuboids (Volume
of a Cuboid
)
tetrahedron hexahedron octahedron dodecahedorn icosahedron Platonic Solids
triangular prism square prism pentagonal prism Prisms
triangular pyramid square pyramid pentagonal pyramid Pyramids
   
Non-Polyhedra:
(if any surface is not flat)
sphere Sphere torus Torus
cylinder Cylinder cone Cone