(Basic) Triangle Theorems

The Triangle Angle Sum Theorem states that the sum of all angles in a triangle is always ______.

• 45°

• 90°

• 180°

• 360°

The Triangle Inequality Theorem states the sum of the lengths of any two sides of a triangle is ________________ the length of the third side.

• greater than

• less than

• equal to

• double

Which of the following does not represent the lengths of the sides of a triangle?

• 2 cm, 6 cm, 7 cm
• 5 cm, 2 cm, 5 cm
• 5 cm, 5 cm, 8 cm
• 3 cm, 10 cm, 15 cm

If BF = 14, DE=?

• 4.6
• 7
• 18
• 14

Tags

CCSS.HSG.CO.C.10

What is a possible third side to a triangle with side lengths of 13 and 4?

• 9
• 12
• 8
• 5

Name the largest angle in this triangle.

• ∠D
• ∠E
• ∠F

Tags

CCSS.HSG.CO.C.10

Name the smallest angle in this triangle.

• ∠A
• ∠B
• ∠C

Tags

CCSS.HSG.CO.C.10

You have 2 minutes. Grab your spiral and work this out!

Find the measure of angle A.

• 75^o

• 60^o

• 30^o

• 38^o

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

• Yes
• No

Which of the following is a possible length for segment AC?

• 10

• 15

• 17

• 9