Monday, November 30, 2009
A triangle is half of a parallelogram. So the formula to find the area of a triangle is (b-base x h-height) divided by 2 (to get the height of a triangle you make a parallel
line from the base to the tallest vertex).
For example the base of the triangle is 2 cm and the Height of the triangle is 4 cm
First you have to multiply the 2 by the 4 to get 8
Then you divide 8 by 2 to get the area which is 4 cm
Here is a site that can help
here is a video
Wednesday, November 25, 2009
- The number of square units contained (inside) in a two dimensional shape.
- Area is the surface space takes up
Area of square or rectangle
- Length * width = area
Area = 6*3
= 18cm Squared
- A 4 sided figure with opposite sides parallel and equal.
Lines are hashmarks that are equal
Arrows are parallel to each other
- A side of a two dimentional closed figure (shape) (b)
A base is any side of a closed figure.
- the perpendicular distance from the base to the opposite side.
Area of parallelogram formula
Base (b) is 5 cm and height (h) 3 cm. Plug these values into the formula.
A=15 cm squared
Find the area of this parallelogram:
A=16 cm squared
Find the area of this parallelogram:
A=48 m squared
What is the shape of the garden?
What is the area of the garden?
Ishaka is going to plant flowers in his garden.
He is going to plant per square metre.
How many flowers does he need to buy?
Find the area of this shape?
If you don't understand here is a website and a video to help you!
Monday, November 23, 2009
An angle that is greater then 90° and less than 180°
An angle that is exactly 90°
An angle that is exactly 180°
The line that divides an angle into equal parts.
(equal angles are marked with the same mark)
Their are 3 ways to make an angle bisector.
1.a) Fold Paper until the 2 lines on your angle meet.
b) Use a ruler to draw a line on a crease.
2.a)Use a compass to make an arc from the vertex that crosses both arms. Label them x and y
b)Make an arc from point x and point y. They must be equal in size.
c) Draw a line from point B to the between the meter section.
3.a)Use a protractor.
b)Measure the < D E F.
c)Divide your measurement by 2. 140÷2= 70°.
d)Make a mark at 70° using a protractor. Label it Q.
e)Join point Q with the vertex with a straight line.
1. Make a 68° angle. Then draw the angle bisector using 2 methods.
2.How could you divide an angle into 4 equal parts ?
You can find out the angle and then divide it by 4.
3.Has each angle been bisected? How do you know ?
No because A is cut in half and B isn't cut into equal parts.
4.What are 2 examples of angle bisectors in the real world?
Pizza and Pie.
Here's a good link that could help you make Angle Bisectors.
Wednesday, November 18, 2009
Bi means two
Sect means to cut
Bisect means to cut in two
A line that divides another line segments in half and has right angles to it.
1st way to make a Perpendicular Bisector:
Fold the paper, so point A is on point B. Draw a line in the crease that you made. Label it C,D. Where they intersect, label it P.
2nd way to make a Perpendicular Bisector:
You have to use a Right Triangle.
Draw a line segment on a piece of paper with a right triangle.
Use the right triangle to find the half mark of the line segment.
Draw another line segment on the half mark, intersecting with the original
Make sure that it is 90 degrees. (use a protractor to check)
3rd way to make a Perpendicular Bisector:
Use a Compass.
Make an arc from point A that is greater than half way.
Make an equal sized arc from point B.
Connect the arc intersection with a straight line.
2.use a right triangle
how to draw perpendicular lines
2.use a protractor
Monday, November 16, 2009
Geometry- Shapes and measurements.
Parallel- Describes two lines in the same plane that never cross, or intersect.
- They are marked using arrows.
Here is a picture of parallel lines:
Perpendicular- Describes lines that intersect at right angles. ( 90°)
- They are marked using a small square
Here's a picture of a right angle
Measure the difference from:
A to B
B to C
E to F
F to G
I to J
J to K
They all are 8.9 cm.
Here's a video about Perpendicular lines
Here's the link: http://www.youtube.com/watch?v=Lc3dPkoCOHc
Identify any parallel lines you can find.
AE // BF, EI // FJ, CG // BF, GK // JF, AI // CK
What d0 you notice about parallel lines? they always are the same distance apart no matter where you measure, as long as you measure a perpendicular line.
Identify any perpendicular line segments.
AE __ DF , FE __ AI , BF __ EG , CG __ FH
What do you notice about perpendicular line segments? they all meet at 90° angles.
#1. Are line segments AC and DF parallel?
#2. Are line segments DF and BE perpendicular?
#3. Are line segments AC and BE perpendicular? How do you know?
#4. Would a line segment joining A to D be parallel to a line segment BE? How do you know?
Monday, November 9, 2009
Friday, November 6, 2009
Lastly, we have a Term Test on Thursday it will cover the entire term's worth of work. Be sure to start studying now, do not wait until the last minute!
Wednesday, November 4, 2009
DON'T FORGET THE HOMEWORK, STUDY FOR THE TEST. *
Tuesday, November 3, 2009
If you don't know what BEDMAS means, make sure to check Kimberly's scribe post!
g) Create a math equation including +, -, ÷, x, brackets and exponents. The answer must be 6 and you can't repeat any digits or use zero.
Here's a video on BEDMAS :
Monday, November 2, 2009
Addition and subtraction are brothers and multiplication and division are sisters.
B E D M A S stands for:
Brackets ( )
1st- brackets ( )
3rd- divide or multiply in order from left to right.
4th- addition or subtraction in order from left to right.
Change this equation so the answer is 158.
The way you change the equation so the answer becomes 158 is you have to put brackets around 6.4+120.