Plane Geometry

If you like drawing, then geometry is for you!

plane


Plane Geometry is about flat shapes like lines, circles and triangles ... shapes that can be drawn on a piece of paper

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

2d pentagon

 

rectangle




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

pi circle diameter

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

Types of Angles
angles

Acute Angles Right Angles Obtuse Angles Straight Angle Reflex Angles Full Rotation





 

Compass  

Using Drafting Tools

protractor

 

Transformations and Symmetry

Transformations:

symmetry drawing

Symmetry:



Activity


 

Coordinates

interactive-cartesian-coordinates

 

 

More Advanced Topics in Plane Geometry

Pythagoras

abc triangle

 

Conic Sections

ellipse draw 3

 

Trigonometry

triangle showing Opposite, Adjacent and Hypotenuse

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