Triangle Inequality Theorem & Congruent Triangles FLASHCARD

Front

What is the Triangle Inequality Theorem?

Back

The Triangle Inequality Theorem states that for any triangle, the sum of the lengths of any two sides must be greater than the length of the third side.

Front

Which set of numbers can represent the side lengths of a triangle? {5,18,13}, {6,17,22}, {16,24,7}, {26,8,15}

Back

{6,17,22} because 6 + 17 > 22, 6 + 22 > 17, and 17 + 22 > 6.

Front

Which set of numbers 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}

Back

{3 cm, 10 cm, 15 cm} because 3 + 10 is not greater than 15.

Front

If ΔPQR ≅ ΔLJK, and PR=2x+6, JL=10 units, LK=3x-6, find the value of x.

Back

x = 12.

Front

What does it mean for two triangles to be congruent?

Back

Two triangles are congruent if they have the same size and shape, which means their corresponding sides and angles are equal.

Front

If two sides of a triangle are 5 cm and 7 cm, what is the range of possible lengths for the third side?

Back

The length of the third side must be greater than 2 cm and less than 12 cm.

Front

What is the definition of congruent triangles?

Back

Congruent triangles are triangles that are identical in shape and size, meaning all corresponding sides and angles are equal.

Front

Given ΔEHG≅ΔKFC, which is a true statement?

Back

EG≅KC.

Front

What is the formula to determine if three lengths can form a triangle?

Back

For lengths a, b, and c, they can form a triangle if a + b > c, a + c > b, and b + c > a.

Front

If two angles of a triangle are 45° and 55°, what is the measure of the third angle?

Back

The third angle is 80° because the sum of angles in a triangle is 180°.