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 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 and pyramids.

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).

	2D Shapes
	Activity: Sorting Shapes
	Triangles
	Right Angled Triangles
	Interactive Triangles

	Quadrilaterals (Rhombus, Parallelogram, etc)
	· Rectangle, Rhombus, Square, Parallelogram, Trapezoid, Kite
	Interactive Quadrilaterals

	Perimeter

	Area
	Area of Plane Shapes
	Area Calculation Tool
	Area of Polygon by Drawing

	Activity: Garden Area
	General Drawing Tool

Polygons

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

Here are some more:

Pentagon

Pentagram

Hexagon


	Properties of Regular Polygons
	Diagonals of Polygons

	Interactive Polygons

The Circle


	Circle
	Pi
	Circle Sector and Segment
	Circle Area by Sectors
	Annulus

	(Advanced) Circle Theorems

	Activity: Dropping a Coin onto a Grid

Symbols

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

Geometric Symbols

Congruent and Similar

	Congruent Shapes
	Similar Shapes

Angles

angles
Types of Angles

Degrees (Angle)
Radians

Congruent Angles
Parallel Lines and Pairs of Angles
Transversal
A Triangle Has 180°

Supplementary Angles
Complementary Angles

Angles Around a Point
Angles on a Straight Line

Interior Angles
Exterior Angles

Interior Angles of Polygons
Exterior Angles of Polygons

Using Drafting Tools

Geometric Constructions

Using the Protractor
Using the Drafting Triangle and Ruler
Using a Ruler and Compass

	Transformations and Symmetry Transformations: Rotation Reflection Translation Resizing Symmetry: Reflection Symmetry Rotational Symmetry Point Symmetry Lines of Symmetry of Plane Shapes Symmetry Artist
	Activity: Symmetry of Shapes Activity: Make a Mandala Activity: Coloring (The Four Color Theorem)

	Tessellations Tessellation Artist


	Coordinates
	Cartesian Coordinates
	Interactive Cartesian Coordinates
	Hit the Coordinate Game

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:

Solids come in two types “Polyhedra” and “Non-Polyhedra”:

Polyhedra :
(they must have flat faces)

	Platonic Solids
	Prisms
	Pyramids

Non-Polyhedra:
(if any surface is not flat)

	Sphere		Torus
	Cylinder		Cone

	Vertices, Faces, and Edges
	Euler’s Theorem

Posted by Ravi Kumar Singh in Geometry

	Pythagoras Pythagoras’ Theorem Pythagorean Triples

	Conic Sections
	Set of all points
	Conic Sections
	Ellipse
	Parabola
	Hyperbola

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

Geometry

Geometry

Point, Line, Plane and Solid