Wednesday, 19 March 2014

Probabilty

Probability means how likely it is that something will happen. For example getting two sixes when you roll a pair of dice (dice is the plural of 'die').


Relative frequency

How often something happens divided by all outcomes.

Circles and Prisms

Circumference of a Circle:

Circumference means the perimeter of a circle


Circumference = 2 × π × Radius

Area = π r2

Prisms

A prism is an object that has the same area all along its length.
 
We can find the volume of a prism by multiplying the area of the base by the length.



Bearings and loci

Objectives 

  • Bearings

  • Locus from a fixed point

  • Constructing a perpendicular bisector

  • (to find the locus that is equidistant from two points)

  • Locus from a line

  • Constructing the bisector of an angle

  • (to find the locus that is equidistant from two lines)


Bearings


Locus from a fixed point

A locus means a path. 'Loci' is the plural of locus. It shows us the path or region that a point can travel according to certain rules. 

The locus of all points at a fixed distance from a line.Watch the video here.



The locus of points that are equidistant from two points: Constructing a Perpendicular Bisector

You can find the method by clicking on the image below:
Watch the video.




The locus of all points that are equidistant from two lines: Bisecting an angle



We use this method to find the locus of all points that are equidistant from two lines.

Some real world examples of loci

Watch a video of how loci apply in the real world.


Tuesday, 18 March 2014

Graphing and Solving Linear Equations

  • The equation of a line
  • Solving two simultaneous equations using a graph
  • Trial and Improvement method to solve an equation

Linear Equations



Solving two simultaneous equations using a graph




Trial and Improvement method to solve an equation

Using this method we 'guess' the first value x and then try other values until we find one that works. Click the image below for an example:




Monday, 10 March 2014

Reflection, Translation, Rotation and Enlargements

Reflection:




Translations






Rotation






Enlargement


Click the image above for more information, watch a video here.

Enlargements






Tuesday, 4 February 2014

Constructions

- Constructing the perpendicular bisector of a line
- Finding the perpendicular from a point to a line
- Bisecting an angle


Constructing a Perpendicular Bisector

You can find the method by clicking on the image below:
Watch the video.




Bisecting an angle

Sunday, 2 February 2014

Angles of Polygons


Interior and Exterior Angles





Exterior Angles of a Polygon
Remember, a polygon is any shape that has 3 or more straight sides (no curves).

Click on the hexagon above to see that:

The exterior angles of any polygon add up to 360°

Interior Angles

90° + 60° + 30° = 180°

80° + 70° + 30° = 180°

It works for this triangle!

Let's tilt a line by 10° ...
It still works, because one angle went up by 10°, but the other went down by 10°
The Interior Angles of a Triangle add up to 180° 






Because there are Two Triangles in a Square
The interior angles in this triangle add up to 180°

(90°+45°+45°=180°)
... and for this square they add up to 360°
... because the square can be made from two triangles!






Because a pentagon has three triangles, the sum of the interior angles add up to 3x180° = 540°






 In general:

The sum of the interior angles of a polygon that has n sides, is:

(n-2) x 180°

Triangles in a circle:

The triangle drawn on the diameter of a circle is always 
a right angled triangle