Showing posts with label Grade 9 Maths. Show all posts
Showing posts with label Grade 9 Maths. Show all posts
Monday, 6 April 2015
Saturday, 11 January 2014
Similar Triangles and Sine, Cosine, Tangent.
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Identify similar shapes
Use Sin, Cos and Tan for acute angles
Similarity
Two shapes are Similar if the only difference is size (and possibly the need to turn or flip one around). Information on similar triangles.See if you can figure out how tall a tree is without having to measure its height:
Right angled triangle ratios
Sine, Cosine and Tangent ratios
Remember:Sohcahtoa
Soh...
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Sine = Opposite / Hypotenuse
|
...cah...
|
Cosine = Adjacent / Hypotenuse
|
...toa
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Tangent = Opposite / Adjacent
|
Click the image below for some extra exercises and further information:
Homework:
P289 Ex1 Q. 6, 11, 13, 16, 17
P293 Ex 2 Q. 17-20
P293 Ex 3 Q. 4, 6, 7, 10, 11, 12
Labels:
Grade 9 Maths
Tuesday, 17 December 2013
Form 9 Christmas Revision
Please review the work we have done in class this year and the material on this blog.
The following site will also be useful in your revision (note that some of the topics may not apply to IGCSE):
Make sure you complete the Christmas revision document which is available at the following link:
http://sdrv.ms/1c8SCuv.
(You can see the document at the end of this post). We will correct this in class at the start of term 2.
Finally please solve the revision problems and check the solutions for the sections listed below (these are from the following website):
http://www.newton.edu.pe/mathematics/Contents/ibrqs2/pag/igcse.htm)
Have a great Christmas and New Year!
Best wishes,
Mr. Healy
The following site will also be useful in your revision (note that some of the topics may not apply to IGCSE):
Make sure you complete the Christmas revision document which is available at the following link:
http://sdrv.ms/1c8SCuv.
(You can see the document at the end of this post). We will correct this in class at the start of term 2.
Finally please solve the revision problems and check the solutions for the sections listed below (these are from the following website):
http://www.newton.edu.pe/mathematics/Contents/ibrqs2/pag/igcse.htm)
Have a great Christmas and New Year!
Best wishes,
Mr. Healy
Labels:
Grade 9 Maths
Wednesday, 11 December 2013
Loci
Objectives
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)
Locus from a fixed point
Constructing a Perpendicular Bisector
You can find the method by clicking on the image below:Watch the video.
Constructing the perpendicular bisector helps you find the locus of points that are equidistant from two points.
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.Homework:
Bearings:
P191 Ex 19 Q 3, 4, 5
Loci:
P194 Ex 20 Q 4, 7, 9, 11
Labels:
Grade 9 Maths
Wednesday, 4 December 2013
Sunday, 1 December 2013
Sunday, 24 November 2013
Monday, 18 November 2013
Scatter Plots, Excel and finding averages
Objectives:
Line of best fit
Use Excel to display data
Calculating the mean, median, mode and range for statistical data.
Frequency polygons
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Scatter Plots
See an Excel tutorial on how to draw a scatter plot and line of best fit
Review of mean, median and mode:

Remember that very large or very small figures in a list of data can affect the mean and the range.
Frequency Polygons
Just as 'averages' can be misleading, look at this link to see how graphs of statistical data can be misleading.
Homework
(P143 Ex 8 Q5)
(P153 Ex 10 Q3, Q11)
P158 Ex 11 Q3
P160 Ex4A Q6
P164/165 Ex 4B Q7
Labels:
Grade 9 Maths
Saturday, 16 November 2013
Handling Data
Objectives:
Construct and interpret:
Pictograms,
Pie charts,
Tally charts and Frequency diagrams,
Grouping data
Conversion Graphs
Pictograms
Pie Charts
Bar Charts & Frequency Diagrams
Conversion Graphs [PDF]
Homework
Pg 133 Ex 4 Q2
Pg 136 Ex5 Q3
Pg 137 Ex6 Q2
Labels:
Grade 9 Maths
Sunday, 10 November 2013
Graphs, gradients and lines
Objectives:
Drawing curved graphs
Calculate the gradient and intercepts of a line
Solving equations graphically
Straight line graphs:
This link shows how a line changes as you change the values.Curved Graphs:
Have a look here to see how changing the constants in an equation changes the shape of the graph.Homework:
Page 56 Ex 11 Q: 5
Page 57 Ex 12 Q: 1 i,j; Q2
Page 59 Ex 14 Q: 9, 10, 15, 23
Page 62 Ex 16 Q: 4
Labels:
Grade 9 Maths
Friday, 8 November 2013
Equations
Objectives:
-Solving Equations: Variable on both sides; fractions; geometrical;
-Drawing linear graphs
Solving Equations:
Homework:
Page 48 Ex 4 Q: 16, 22,28
Page 48 Ex 5 Q: 13, 16, 19
Page 49 Ex 6 Q: 21, 26, 31
Page 49 Ex 7 Q: 5
Page 50 Ex 8 Q: 5, 12
Page 51 Ex 9 Q: 5, 7, 11
Page 54 Ex 10 Q:11
Labels:
Grade 9 Maths
Monday, 28 October 2013
Angles, Lines and Polygons
Objectives:
To know that the angles of a triangle add up to 180°
Angle properties of parallel lines
To know that the sum of the interior and exterior angles of quadrilateral add up to 360°
Tangents and triangles in a semi-circle
An Interior Angle is an angle inside a shape.
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A tangent to a circle is a line which just touches the circle.
Remember:
A tangent is always at right angles to the radius where it touches the circle.
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To know that the angles of a triangle add up to 180°
Angle properties of parallel lines
To know that the sum of the interior and exterior angles of quadrilateral add up to 360°
Tangents and triangles in a semi-circle
The angles of a triangle add up to 180°
Angle properties of parallel lines
Interior Angles of Polygons
An Interior Angle is an angle inside a shape.
Triangles
The Interior Angles of a Triangle add up to 180°
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°
|
Quadrilaterals (Squares, etc)
(A Quadrilateral has 4 straight sides)90° + 90° + 90° + 90° = 360° | 80° + 100° + 90° + 90° = 360° |
A Square adds up to 360°
|
Let's tilt a line by 10° ... still adds up to 360°!
|
The Interior Angles of a Quadrilateral add up to 360° |
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! |
Exterior angles of a polygon add up to 360
Names of polygons
The angle between the tangent and radius is 90°
A tangent is always at right angles to the radius where it touches the circle.
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The triangle drawn on the diameter of a circle is always a right angles triangle
We could also rotate the shape around 180° to make a rectangle! It is a rectangle, because all sides are parallel, and both diagonals are equal. And so its internal angles are all right angles (90°). |
Labels:
Grade 9 Maths
Sunday, 27 October 2013
Volumes, angles and triangles
28/10/2013
Objectives:
Calculate volumes of prisms and cuboids
Determine volume and surface area of cylinders
Constructing triangles given sides and angles
What are 'nets'?
Angle Facts
Cuboids
A cuboid is a box-shaped object.
Prisms
A prism has flat sides and the same cross section all along its length.
Cylinders
Using a protractor
Nets
A 'net' is the shape you get when you cut along the edges of a three dimensional object and lay it out flat.Other objects:
Angle Facts
>>>>>>>>60 second challenge<<<<<<<<<<<
Summarise in your copybook what we have learned today.
Labels:
Grade 9 Maths
Saturday, 26 October 2013
Circles & Areas
Sunday 27 October 2013
Objectives:
- Review of circle terms, circumference and area.
- Calculate the areas of more complicated shapes
- Areas of rectangles and triangles
- Definition and areas of parallelograms and trapeziums
Circles:
Copy the diagram and label each of [AB], [CD], [EF], [GH]Answer is here.
Copy the picture below, label the green and blue sections:
Answer is here.
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Circle: Area and circumference
Area of a rectangle:
Area of a triangle:
More: Area of a triangle inside a rectangleArea of a trapezium:
Note: this shape is also known as a trapezoid.Area of a parallelogram:
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Bring your protractors tomorrow please!
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Labels:
Grade 9 Maths
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