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.|
A Point has no dimensions, only position
A Line is one-dimensional
A Plane is two dimensional (2D)
A Solid is three-dimensional (3D)
Why do we do Geometry? To discover patterns, find areas, volumes, lengths and angles, and better understand the world around us.
Plane Geometry is all about shapes on a flat surface (like on an endless piece of paper).
A Polygon is a 2-dimensional shape made of straight lines. Triangles and Rectangles are polygons.
Here are some more:
Circle Theorems (Advanced Topic)
There are many special symbols used in Geometry. Here is a short reference for you:
Types of Angles
Using Drafting Tools
Trigonometry is a special subject of its own, so you might like to visit:
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
There are two main types of solids, "Polyhedra", and "Non-Polyhedra":
Polyhedra (they must have flat faces):
|Cubes and |
of a Cuboid)
Non-Polyhedra (when any surface is not flat):