Triangle Inequality Theorem
Triangle by angles
When given perimeter
When given x
Mixed review
100

3,3, 6

Triangle? Why or why not? 

No, because 3+3=6

a+b>c 

100

45, 45, ____


What type of triangle

90


right triangle, also isosocles 

100

3x, x, 3x

Perimeter of 42

What do we set = to each other?

What is x?

7x=42 

x=6

100

2x+4, 2x+2, 2x

x=4

What are the side lengths

What's the perimeter

12, 10, 8 

30

100

2x+10=50

What's x

x=20

200

10, 20, 5


Triangle? Why or why not? 

No, because 10+5<20

a+b>c

200

15, 65, ___


What kind of triangle (by angle)

100


Obtuse

200

2x+4, 2x+2, 2x

Perimeter of 30

What do we set = to each other?

What is x?

6x+6=30

x=4

200

3x-3, 3x+1, 10x-30

x=5

What are the side lengths?

What is the perimeter

12, 16, 20

Perimeter: 48

12, 16, 20

200

2(3x+6)=60

What's x

x=8


300

30, 30, 30

Triangle? Why or why not? If so, what kind? 

Yes, a+b>c 

equilateral

300

44, 66, ____


What type of triangle by angle? 

70 

acute

300

5x+2, 11x+3, 8x-3

Perimeter of 98

What do we set = to each other?

What is x?

24x+2=98


x=4

300

A square with side lengths 2x+3

x=4

What are the side lengths

What's the perimeter


11

44

300

y=2/3x+5

What are two coordinates (x, y) I can plot? 

(0,5)

(3,7) or (-3,3)

400

15, 15, 25

Triangle? Why or why not? If so, what kind? 

Yes, 15+15>25

a+b>c

isosceles


400

x, 3x, 2x


What type of triangle

6x=180

x=20

20, 60, 40

acute, also scalene

400

2x, 4x+1, 6x-5

Perimeter of 26

What do we set = to each other?

What is x?

12x-4=26

x=2.5 or 2 1/2

400

An octagon with all side of 3x-5

x=5

what's each side length?

What's the perimeter? 

10

80

400

3x+5y=15

What are my x and y intercepts

x: (5,0)

y: (0,3)