Download 5-5 triangle inequalities.notebook

5­5 triangle inequalities.notebook
November 28, 2012
The smallest side is
opposite from the
smallest angle.
Inequalities in
One Triangle
A
60
70
50
B
Oct 27­9:25 AM
Oct 27­9:19 AM
The largest side is the side opposite the largest angle
A
C
60
Identify the sides in order from smallest to largest
P
57
90
33
R
Q
T
50
B
70
30
C
L
124
M
Oct 27­1:21 PM
Oct 27­1:27 PM
The smallest angle is opposite from the smallest side
9
G
B
The largest angle is opposite from the largest side.
P
7
R
3
15
12
11
C
Q
Oct 27­1:36 PM
Oct 27­1:42 PM
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5­5 triangle inequalities.notebook
November 28, 2012
Are you ready for a challenge???
Write the angles in order from largest to smallest
Y
13
V
R
7
16
15
Let's see who's got SWAG?
V
21
10
W
U
Oct 27­1:46 PM
Oct 27­1:49 PM
If you have two sides of a triangle, the third side can be a variety of lengths.
What is the shortest side?
for example
B
13
C
50
A 64
18
66 56
D
18
13
Oct 27­2:51 PM
Oct 27­2:54 PM
To find the possible measures of the third
What are the possible side lengths of a triangle with sides 9 and 15?
side, you add and subtract the two known
sides.
13
18
18 ­ 13 = 5
18
13
18 + 13 = 31
What are the possible side lengths of a triangle with sides 20 and 40?
So the possible lengths of the sides of a triangle
with sides 13 and 18 can be 5 < x < 28
Oct 27­3:01 PM
Oct 27­3:08 PM
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5­5 triangle inequalities.notebook
Can you make a triangle with any 3
line segments?
November 28, 2012
To know if 3 line segments form a
triangle, you add the 2 smallest numbers,
and it has to be BIGGER than the largest
number.
example... 14, 20, 3
14 + 3 = 17
This is not a triangle because the sum of the two smallest numbers is not larger than the largest side.
Oct 27­3:09 PM
Does 8, 11, 19 form a triangle?
NO
Because the sum
of the two smallest sides are not larger than the largest side.
Oct 27­3:20 PM
Oct 27­3:16 PM
Try these on your own.
1.
5, 5, 5
2.
10, 17, 9
3.
31, 11, 20
4.
15, 8, 7
Oct 27­3:25 PM
Bookwork p. 336: 4, 5, 18, 19
p. 337: 26 ­ 31, 42 ­ 53
Homework: p. 33: 3 - 12
Oct 27­3:29 PM
Oct 27­3:41 PM
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