Download Lesson 1.3 What`s a Widget notes

1.3 What’s a Widget?
Characteristics of a Good Definition:
1.
Classify your term. (What is it?)
2.
Differentiate your term. (How does it differ from others in that class?)
3.
Test your definition by looking for a counterexample.
(Types of Lines)
(jk) - Two or more lines lying in the same plane that never
intersect.
j
k
(nm) - Two lines that intersect to form right angles.
n
m
(Types of Angles)
– An angle whose measure is exactly 90.
– An angle whose measure is greater than 0 but less than 90.
– An angle whose measure is greater than 90 but less than 180.
– An angle whose measure is exactly 180.
Geometry Lesson 1.3: What’s a Widget?
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– Two nonadjacent angles formed by two intersecting
lines.
2
3
1
4
1 & 3 are vertical angles
2 & 4 are vertical angles
– Two adjacent angles whose distinct sides lie on the
same line.
5
6
5 & 6 are a linear pair of angles
- Two angles whose measures have a sum of 90.
- Two angles whose measures have a sum of 180.
Geometry Lesson 1.3: What’s a Widget?
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Example 1: Identify each pair of parallel lines and each pair of perpendicular lines.
j
k
l
m
n
o
Example 2: Identify each angle as acute, right, obtuse, or straight.
B
A
C
D
E
F
Geometry Lesson 1.3: What’s a Widget?
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Example 3: Identify each pair of vertical angles.
G
A
E
B
C
F
1
6
D
M
H
2
3
P
5
4
J
K
Example 4: Identify each linear pair angles.
G
A
E
B
C
F
1
6
D
M
H
2
3
P
5
4
J
K
Geometry Lesson 1.3: What’s a Widget?
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Example 5: Find the (i) complement and (ii) supplement of each angle.
a) 25°
b) 45°
c) 85°
i)
i)
i)
ii)
ii)
ii)
d) 125°
e) 90°
f) 2°
i)
i)
i)
ii)
ii)
ii)
g) 75°
h) 95°
i) 18°
i)
i)
i)
ii)
ii)
ii)
Homework: pp. 51 – 52 => 1 – 9; 11 – 20
Geometry Lesson 1.3: What’s a Widget?
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