edm 1 lines and angles
TRANSCRIPT
![Page 1: Edm 1 lines and angles](https://reader035.vdocument.in/reader035/viewer/2022062300/555312ffb4c905533f8b53bb/html5/thumbnails/1.jpg)
Lines and Angles
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Lines are everywhere…
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Line segments can be measured from beginning to end.
We mark a line segment with points
Those points are labeled with letters
A B
We can name this line segment either:
AB BA
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Lines are different from line segments.We can see the beginning and ending of a line segment.Lines extend on forever
To show the difference between a line and a line segment we use arrows instead of points
Lines vs. Line Segments
A B
We name a line by showing the arrows: AB
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A
B
C
D
Two line segments are shown here
AB CD
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When lines or line segments meet…
A
B
C
D
They intersect to form angles…
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C
DA
B
The point at the intersection is called the vertex.
E
When we name the angle, the vertex must be in the middle
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C
DA
B
The point at the intersection is called the vertex.
E
When we name the angle, the vertex must be in the middle
AED or
DEA
Point E, the vertex, is always in the middle
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Notice any angles?
H
J
I
A
B
C
XY
Z
P
Q
R
Name these angles…
BAC
XYZ
PQR
JHI
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A
B
C
D
When 2 line segments meet to form a 90° angle they called perpendicular line segments
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A
B
C D
Perpendicular lines intersect to form a 90° angle also referred to as a right angle.You can check if the angle right by holding up a piece of notebook paper.
90°90°
90°90°
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90°
Where do we see right angles?
PerpendicularA
B
C D
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A
B
C D
Perpendicular
Where do we see right angles?
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Let’s Look at the Strata Center again…
Notice many perpendicular lines?
A
B
C D A
B
C
D
Not quite 90°
Smaller than 90° again.
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A
B
C D A
B
C
D
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A
B
C D A B
CD
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A
B
C D A B
CD
Both of these angles are smaller than 90° Angles smaller than 90° are called acute
Acute Angle = Less than 90°
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What about angles larger than 90°?
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What about angles larger than 90°?
Notice all of the extra room?
Angles larger than 90° are called obtuse
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If you extend these two lines segments will they ever touch?
Right, if they did what might happen?
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When two line segments on the same plane never touch they are called
Parallel
Lots of parallel lines
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Do these lines intersect?
But, if you extend them outward, would they intersect?
Are these lines parallel?
No, but actually they are. It’s just the angle of the picture.
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Examples of Parallel Lines