## Thursday, May 31, 2012

## Wednesday, May 30, 2012

## outliers

small numbers that don't go with bigger numbers

eg 1 98 99 20

## median

the middle number in a set of data after setting it from least to greatest

## mode

the most frequently occurring number in a set of data

## Monday, May 21, 2012

### Probability

-likelihood or the chance of an event occuring

eg.

flipping a coin, rolling a die, etc.

eg.

flipping a coin, rolling a die, etc.

### Line Segment

-piece of a line with starting and end points

### Intersecting

Lines in the same plane that meet or cross.

### Height of a Triangle

Height of a Triangle

Here is an example of the height of a triangle:

Height of a Triangle is a perpendicular line from base to opposite angle.

Angle Bisector

And Example of An Angle bisector:

This is an Angle Bisector.

And angle Bisector is a line that Divides an angle into two equal parts.

-Equal angles are marked with the same angle.

Steps To make an "Angle Bisector"

1. Compass point at the angle vertex make an arc through both arms.

2. Compass point at the vertex of your first arc and make one arm make another arm.

3.Repeat step 2. But from the other arm.

4.Draw line from arc intersecting to angle vertex

### Perpendicular Bisector

**Perpendicular Bisector**

This is a picture of an perpendicular bisector

A perpendicular Bisector is a line that divides another line segment in half and meets at right angle.

-Equal line segments are hash marks.

**How to make a Perpendicular**

**Bisector**

1. Open compass to just over half way of a line segment.

2. Sharp point at "A" Make an Ark

3. Sharp Point at "B" make and Ark

4. With ruler join the two intections

## Sunday, May 20, 2012

### Area of a triangle

Every triangle is half of a parallelogram. We know the formula to find the area of a parallelogram is base times height. So the formula for the area of a triangle is half the area of a parallelogram. The formula for area of a triangle is base times height divided by 2.

Formula for area of a triangle is: b x h / 2

Formula for area of a triangle is: b x h / 2

Here's a link on area of a triangle.

### Base and height

Base- Any side of a closed 2 dimensional figure. Common symbol is "b".

Height- The perpendicular distance from the base to the opposite side. Common symbol is "h".

Height- The perpendicular distance from the base to the opposite side. Common symbol is "h".

### Area of Parallelogram

To find the area of a parallelogram you have to to use a formula. That formula is base times height.

FORMULA: b x h

Base -any side of a closed 2 dimensional figure/shape.

FORMULA: b x h

Base -any side of a closed 2 dimensional figure/shape.

-common symbol is b.

Height -the perpendicular distance from the base to the opposite side.

-common symbol is h.

Here's a link for more information on the area of the parallelogram.

### Central Angle

Central Angle- An angle formed by 2 radii with the vertex (2 lines meet or point) at the center of a circle.

### Parallelogram

Parallelogram- a four sided figure with opposite sides parallel and equal in length.

Here's a link on parallelograms.

### Perpendicular Bisector

Perpendicular- lines in the same plane that intersect at 90 degree angles.

Bisector- a line that divides another line segment in half and meets at right angle.

-equal line segments are shown with hash marks.

Perpendicular Bisector- a line that divides another line segment in half and meets at right angle.

Bisector- a line that divides another line segment in half and meets at right angle.

-equal line segments are shown with hash marks.

Perpendicular Bisector- a line that divides another line segment in half and meets at right angle.

-equal line segments are shown with hash marks.

Here's a link on Perpendicular Bisectors.

### Circumference

Circumference- is the perimeter of a circle. Distance around the circle.

Formula for circumference:

C=2πr

C=πd

Here's a link about circumference for more information.

## Sunday, May 13, 2012

## Thursday, May 10, 2012

## Monday, May 7, 2012

## Sunday, May 6, 2012

### Central Angle

### What are the formulas we use to get the area and circumference of a circle?

- D=2r.
- D/2=R.
- C=2πr.
- A=πr(squared).
- C=πd.

## Saturday, May 5, 2012

### Definition of 'Height'

Height: -The perpendicular distance from the base to the opposite side.

-Common symbol is '

-Common symbol is '

*h*'.### Definition of 'Base'

Base: -Is any side of a closed two-dimensional figure (or shape).

-It's common symbol is '

-It's common symbol is '

*b*'.### How to find the Area in a Circle

As an example to show you step-by-step, we'll use r(adius)=12 cm. There is one formula to find the area.

1) A(rea of circle)=πr

2)A=3.14 x (12

3)A=3.14 x 144 ('

4)A=452.2 cm

Hope this helped you!

1) A(rea of circle)=πr

^{2}(Always write the formula your using as your first line)2)A=3.14 x (12

^{2}) (Write out the second line like so. It will usually specify whether or not you substitute π for 3.14, in this case it does. Put r^{2}into brackets, meaning in the next line, you will do this first)3)A=3.14 x 144 ('

^{2}' means to square. Meaning you have to multiply the number by itself not by 2, lots of people get confused by this. Your third line should look like this)4)A=452.2 cm

^{2}(You then multiply 3.14 by your radius squared. There you have it! your answer! Don't forget to add what it's measured in plus squared)Hope this helped you!

## Friday, May 4, 2012

### How to Make a Perpendicular Bisecr Using a Compass

####
__How to make a perpendicular bisect using a compass__

__How to make a perpendicular bisect using a compass__

#### 1.Open compass to just over half way of the segment

#### 2.Sharp point at point A make an arc

#### 3.Sharp point at point B make an arc

#### 4.With ruler join the 2 intersections of the arcs

### How to find the Circumference

As an example to show you step-by-step, we'll use the number

1) C(ircumference)=2π

2) C=2 x π x

3) C=6.28 x

4) C=28.8 cm (Multiply 6.28 x whatever your radius is and there you have it! the circumference. It will specify if you should round your answer or not, I've rounded the answer to the nearest tenth. Don't forget to include what it's measured in if it said)

I hope this helped you!

*r(adius)*=4.6 cm. I'll show you how to find the circumference if you have the*radius*.1) C(ircumference)=2π

*r*(This is the formula we use to find the circumference, always write this down first when beginning)2) C=2 x π x

*4.6*(Write out the second line like so but, substitute*r*for whatever your*radius*is)3) C=6.28 x

*4.6*(Multiply 2 x π (in most cases it will say to use 3.14 for π), you should get the answer of 6.28. Write that in the place of 2 x π like so)4) C=28.8 cm (Multiply 6.28 x whatever your radius is and there you have it! the circumference. It will specify if you should round your answer or not, I've rounded the answer to the nearest tenth. Don't forget to include what it's measured in if it said)

I hope this helped you!

### Common terms in Circles

Diameter: Is the distance across a circle through it's circle.

Radius (

Circumference: Is the perimeter of a circle, or the distance around the circle.

Area: Is the inside of the perimeter (circumference), or what's inside the circle.

Radius (

*or 'radii' for plural)*: Is the distance from the centre of a circle to its outer edge (sort of like a spoke in a wheel).Circumference: Is the perimeter of a circle, or the distance around the circle.

Area: Is the inside of the perimeter (circumference), or what's inside the circle.

## Tuesday, May 1, 2012

### Perpendicular bisector

Perpendicular bisector- a line that divides another line segment in half and meets at right angles

- equal line segments are shown with hash marks

### What is a radius?

Radius- (plural is radii) the distance from the center of a circle to its outer edge.

**A video how to find the radius of a circle when given the circumference**### What is a Central Angle?

CENTRAL ANGLE - an angle formed by 2 radii with the vertex (2 lines meet or point) at the centre of a circle.

To learn more about central angles, click this link.

To learn more about central angles, click this link.

### What does Perpendicular Bisector?

Perpendicular Bisector

-a line that divides another segment in half and meets at right angles.

-a line that divides another segment in half and meets at right angles.

### Central Angle

__Central Angle__**- an angle formed by 2 radii with the vertex (2 lines meet or point) at the centre of a circle.**

**click here for a link about central angle.**

### What's a radius?

Radius is the part of a circle that starts from the center to the side of the circle.

The formula for radius is d/2.

e.g

the diameter is 66cm, what is the radius?

r=d/2

r=66/2

r=33cm.

### Area of a circle

__Area of a circle__- the area of the circle is the number of square units inside that circle.**Formula:**

**A = πr²**

**click here for a link about area of a circle.**

**A video about Area of a circle:**

Subscribe to:
Posts (Atom)