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PPT – E6 Students will be expected to recognize, name, describe, and represent perpendicular lines/segments, bisectors of angles and segments, and perpendicular-bisectors of segments. PowerPoint presentation | free to download - id: 6cdde0-YzEyM

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E6 Students will be expected to recognize, name,

describe, and represent perpendicular

lines/segments, bisectors of angles and segments,

and perpendicular-bisectors of segments.

What are the characteristics of a line in

geometry?

A line is straight and extends in both directions

forever. It has no definite endpoints.

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What defines a line segment in geometry?

A

B

A line segment is straight and has two definite

endpoints. This is line segment AB or BA.

What are perpendicular lines?

Where do we see perpendicular lines in the real

world?

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Student Activities

- How can you use a mira to draw perpendicular

lines? - Draw a line segment and place the mira across it,

moving the mira until the image of the part of

the segment on one side of the mira falls on the

segment on the other side. The line on which the

mira sits is perpendicular to the original line

therefore, place a pencil against the beveled

edge of the mira and draw in this perpendicular.

What does bisect mean?

Bisect means to divide in half.

What can be bisected in geometry?

Line segments and angles can be bisected.

A perpendicular-bisector is a line segment that

cuts through a second segment or line forming

right angles. It also cuts the segment in half or

bisects it.

Try to use your mira to show a

perpendicular-bisector.

- Explanation When the image of the endpoint of

the segment falls on the other endpoint, the mira

is bisecting the segment therefore, the line on

which the mira sits would be the

perpendicular-bisector of the segment.

What are parallel lines?

Where do we see parallel lines in the real world?

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Use two straws to make the following arrangements

- parallel to one another
- intersecting
- perpendicular at an end point of one straw
- perpendicular at endpoints of each straw
- one straw perpendicular to the other straw at its

midpoint - one straw bisecting the other straw but not

perpendicular - each straw bisecting the other straw but not

perpendicular - one straw bisected by the other straw and

perpendicular - each straw bisecting the other straw and

perpendicular

Bisecting Angles Using Three Methods

- Bisect the first angle given to you by folding

one arm onto the other. - Bisect the next angle by using a mira to find

where one arm would reflect onto the other when

it is placed through the vertex - Bisect the third angle by using a protractor to

measure the angle. Then bisect it. - Practise the three methods by bisecting the other

angles on the sheet provided to you.

- E6.1 Draw a right angle, an acute angle, and an

obtuse angle. Use only a mira to draw in the

bisector of each angle. Check your results by

paper folding and by measuring the angles with a

protractor.

- E6.2 Use the capital letters of the alphabet

that use only segments. Find examples of

bisectors of segments, perpendicular segments,

and perpendicular-bisectors. Share your findings.

- E6.3 Draw, without measuring, a segment that is

approximately 10cm long. Next, construct a

perpendicular bisector of this segment, using

only a mira.

- E6.4 Fold sheets of paper in half and then in

half again. Open them up to reveal the folds and

draw in segments along these folds. Describe the

relationship between these two segments.