10-7 Triangle Inequality Theorem

Triangle Inequality Theorem

Objective:

Students will apply the Triangle Inequality Theorem to determine if a given set of three side lengths form a triangle.

Open Ended

Which one doesn't belong?

Explain your reasoning.

A, B, D, or D doesn't belong because ...

FAST Review Questions

Multiple Choice

• A

• B

• C

• D

Multiple Choice

• A

• B

• C

• D

Multiple Choice

• A

• B

• C

• D

Multiple Choice

• Yes

• No

Multiple Choice

If the sides of a triangle are 7, 24, and 25, is it a right triangle?

• yes
• no

Multiple Choice

Can sides 12, 10 and 7 make a right triangle?

• yes

• No

Sides of a triangle

Since,

3+4>5, TRUE

3+5>4, TRUE

5+4>3 TRUE

Side lengths 3, 4, and 5 form a triangle.

​Since 3 + 4 < 9, side lengths 3, 4, and 9 DO NOT form a triangle.

Will the following lengths form a Triangle?

7, 13, 18

Will the following lengths form a Triangle?

8, 12, 25

Will the following lengths form a Triangle?

8, 14, 8

Will the following lengths form a Triangle?

17, 3, 19

Will the following lengths form a Triangle?

15, 33, 38

Will the following lengths form a Triangle?

7, 13, 7

Multiple Choice

Determine if the 3 numbers can be measures of the sides of a triangle. 4, 16, 19

• Yes

• No

Multiple Choice

Determine if the 3 numbers can be measures of the sides of a triangle. 9, 11, 20

• Yes

• No

Multiple Choice

Determine if the 3 numbers can be measures of the sides of a triangle. 9, 12, 20

• Yes

• No

Multiple Choice

Determine if the 3 numbers can be measures of the sides of a triangle. 6, 14, 21

• Yes

• No

Poll

^{Find the missing side}

• 9

• 41

• 6.4

• 3

Multiple Select

Which two sets of side lengths does not form a right triangle?

• 38, 80, 90

• 16, 63, 65

• 36, 77, 85

• 14, 15, 29