Showing posts with label Grade 8 Maths. Show all posts
Showing posts with label Grade 8 Maths. Show all posts
Wednesday, 19 March 2014
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 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.
Labels:
Grade 8 Maths
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:
Labels:
Grade 8 Maths
Monday, 10 March 2014
Tuesday, 4 February 2014
Constructions
- Constructing the perpendicular bisector of a line
- Finding the perpendicular from a point to a line
- Bisecting an angle
Watch the video.
- 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
Labels:
Grade 8 Maths
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°
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
Labels:
Grade 8 Maths
Monday, 13 January 2014
Areas and volumes
Objectives:
Area of rectangles and triangles
Area of parallelograms and trapeziums
Volume of cuboids
Parts of a circle, circumference and area.
Area of a rectangle:
Area of a triangle:
More: Area of a triangle inside a rectangleArea of a parallelogram:
Area of a trapezium:
(Note: this shape is also known as a trapezoid, but for your exam just use trapezium!)Cuboids
A cuboid is a box-shaped object. Click the image below for more information.
V = l × w × h
Nets
A 'net' is the shape you get when you cut along the edges of a three dimensional object and lay it out flat.Parts of a circle:
Copy the picture below, label the green and blue sections:
Answer is here.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Circle: Area and circumference
Homework:
P162 Ex 18.1 Q 3
P165 Ex 18.2A Q3
P165 Ex 18.2B Q 1b, Q2b
P170 Ex 18.3B Q 1, 2
P172 Ex 18.4 Q 3
P174 Ex 18.5A Q 1 - 9
P176 Ex 18.5B Q 1c, 1d, 2c, 2d.
P177 Ex 18.5C d, e
Labels:
Grade 8 Maths
Tuesday, 7 January 2014
Angle Properties
Identify: Supplementary, vertically opposite, corresponding and alternate angles.
Know that angles of a triangle add up to 180°
Know that the exterior angle of triangle is equal to the sum of the two interior opposite angles.
Know that angles of a quadrilateral add up to 360°
Supplementary Angles (add to 180°)
Vertically Opposite Angles..... are equal
Corresponding Angles (look for an 'F' shape)...... are equal
Alternate Angles (look for a 'Z' shape)....are equal
Angles of a triangle add up to 180°
A + B + C = 180°
Exterior angle of triangle is equal to the sum of the two interior opposite angles.
C = A + B
Angles of a quadrilateral add up to 360°
80° + 100° + 90° + 90° = 360°
Homework:
P153 Ex 16.4C Q3-6
P156 Ex 17.1B Q4-8
P158 Ex 17.2 Q3, 5, 6
P160 Ex 17.3A Q3, 4
P160 Ex 17.3B Q1, 4
Labels:
Grade 8 Maths
Tuesday, 17 December 2013
Form 8 Christmas Revision
Please download the Christmas revision document available at the following link:
http://sdrv.ms/1c8Sc7r
Please review the work we have done this year and on here.
Have a great Christmas and New Year!
Best wishes,
Mr. Healy
http://sdrv.ms/1c8Sc7r
Please review the work we have done this year and on here.
Have a great Christmas and New Year!
Best wishes,
Mr. Healy
Labels:
Grade 8 Maths
Tuesday, 19 November 2013
Fractions, Decimal and Percentages
Objectives:
Convert fractions to decimals
Change decimals to fractions
Putting fractions in order -converting to decimals -common denominators
Calculating a fraction of a quantity
Mixed numbers
Multiplying and dividing by fractions
Percentages
Fractions Review
Decimals
Percentages
Homework
Exercise 15.1A | Fractions to Decimals |
Q3 | |
Q6 | |
Exercise 15.1B | Decimals to fractions |
Q3, 4 | |
Exercise 15.1 C | Ordering |
Q 1, 2 | Q 3, 4 |
Exercise 15.2A | Mixed Numbers |
Q 4, 5, 6 | |
Exercise 15.2B | + & - |
Q 4, 6 | |
Exercise 15.2C | x & ÷ |
Q 3, 4 Q 9, 10 |
Exercise 15.3A |
Percentages |
|
Q 3, 4 |
|
|
Exercise 15.3 B |
|
Q 3, 4 |
|
Q 9, 10 |
Labels:
Grade 8 Maths
Monday, 11 November 2013
Statistical Calculations
Objectives:
Calculating the mean, median, mode and range for statistical data.
Know which is the best to use.
Review of mean, median and mode:

Large and small values
You need to know that very large or very small figures in a list of data can affect the mean and the range.The median and the mode are less affected.
Homework:
Page 112 Ex. 12.1 Q:1
Page 115 Ex 12,2 Q:2
Labels:
Grade 8 Maths
Saturday, 2 November 2013
Letters as numbers and solving equations
Objectives:
Link numbers to letters.
Solve equations: know that what we do on one side of the equation we must do on the other.
Write mathematical sentences.
Linking numbers to letters.
Try the quiz:
Labels:
Grade 8 Maths
Monday, 28 October 2013
Order of operations, Indices
Order of Operations:
Order of operations with numbers and letters:
What is the meaning of "Like and unlike terms"?
Solving Equations:
Labels:
Grade 8 Maths
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