Mathematics 8 Quiz

Which theorem states that "If two angles of a triangle are not congruent, then the larger side is opposite the larger angle"?

• Triangle Inequality Theorem

• Side-Angle Relationship Theorem

• Exterior Angle Inequality Theorem

• Hinge Theorem or SAS Inequality Theorem

The sum of the lengths of any two sides of a triangle is always _________.

• half of the length of the third side

• equal to the length of the third side

• less than the length of the third side

• greater than the length of the third side

Triangle XYZ has angles ∠X = 40°, ∠Y = 75°, and ∠Z = 65°. Which of the following is true about the sides?

• XY is the longest side because it is opposite the largest angle.

• YZ is the longest side because it is opposite the largest angle.

• XZ is the longest side because it is opposite the largest angle.

• All sides are equal since the sum of angles is 180°.

A student is given three straws with lengths 9 cm, 15 cm, and 20 cm. She wants to form a triangle by connecting the ends of the straws. Which of the following is correct?

• A triangle can be formed because 9 + 15 is greater than 20.

• A triangle cannot be formed because 15 + 20 is not greater than 9.

• A triangle can be formed only if the angles are right angles.

• A triangle cannot be formed because the sum of all sides must be at least 50 cm.

A carpenter is cutting three wooden planks to form a triangular frame. The planks measure 12 cm, 7 cm, and 4 cm. Before assembling, he checks if they can form a triangle. What should he conclude?

• Yes, because all three sides have different lengths.

• Yes, because the sum of any two sides is always greater than the third side.

• No, because the sum of 4 cm and 7 cm is not greater than 12 cm.

• No, because the sum of all three sides must be at least 25 cm.

Ruel, Geralyn, Reymond and Shiela were given a 24-inch piece of stick each. They were instructed to create a triangle. Each cut the stick in their own chosen lengths as follows: Ruel-8 in, 8 in, 8 in; Geralyn-5 in, 7 in, 12 in; Reymond-9 in, 7 in, 8 in; and Shiela-6 in, 8 in, 10 in. Who among them could NOT be able to form a triangle?

• Geralyn

• Ruel

• Reymond

• Shiela

A triangle has side lengths x, 7, and 10. If it follows the Triangle Inequality Theorem, which of the following could be a possible value of x?

• 1

• 2

• 3

• 5

Which of the following sets of side lengths can form a triangle?

• 3 cm, 4 cm, 5 cm

• 2 cm, 7 cm, 10 cm

• 8 cm, 3 cm, 12 cm

• 5 cm, 2 cm, 8 cm

A triangle has sides measuring 5 cm and 12 cm. Which of the following cannot be the third side?

• 6 cm

• 10 cm

• 15 cm

• 18 cm

If a triangle has side lengths 6 cm and 9 cm, what is the possible range for the third side?

• Less than 6 cm but greater than 3 cm

• Less than 9 cm but greater than 6 cm

• Less than 15 cm but greater than 3 cm

• Less than 18 cm but greater than 0 cm