Triangle Inequality

Does a triangle with these side lengths exist?

15, 12, 9

• Yes

• No because 12 + 9 is greater than 15

• No because 15 - 9 is NOT greater than 12

• No because 15 - 12 is NOT greater than 9

Can the sides of a triangle have lengths 3, 8, and 9?

• Yes

• No because 3 + 8 is greater than 9

• No because 9 - 3 is NOT greater than 8

• No because 9 - 8 is NOT greater than 3

Can the sides of a triangle have lengths 3, 4, and 9?

• Yes

• No because 3 + 4 is NOT greater than 9

• No because 9 - 3 is NOT greater than 4

• No because 9 - 4 is NOT greater than 3

Can the sides of a triangle have lengths 4, 11, and 13?

• Yes

• No because 4 + 11 is greater than 13

• No because 13 - 11 is NOT greater than 4

• No because 13 - 4 is NOT greater than 11

Which values are possible for the third side to a triangle with side lengths of 13 and 4?

• 9

• 12

• 10

• 14

• 17

Which values could be used for the third side to a triangle with side lengths of 13 and 4?

• 9

• 12

• 8

• 17

• 15

Which values are possible for the third side to a triangle with side lengths of 5 and 5?

• 9

• 10

• 11

• 5

• 8

Which of the following would NOT work to make a triangle with the two side lengths of 2 and 6?

• 6
• 7
• 5
• 4

Tags

CCSS.7.G.A.2

Name the largest angle in this triangle.

• ∠D

• ∠E

• ∠F

• All angles are equal

Name the smallest angle in this triangle.

• ∠A

• ∠B

• ∠C

• All angles are equal.