Triangle Inequality Review

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

Can the side lengths 4 cm, 7 cm, and 10 cm form a triangle?

Back

Yes, because 4 + 7 > 10, 4 + 10 > 7, and 7 + 10 > 4.

Front

If two sides of a triangle are 9 cm and 12 cm, what is the range of possible lengths for the third side?

Back

The length of the third side must be greater than 3 cm and less than 21 cm.

Front

Which of the following cannot be the length of a side of a triangle if the other two sides are 9 cm and 12 cm? 5 cm, 21 cm, 10 cm, 20 cm?

Back

21 cm cannot be the length of the third side.

Front

What is the minimum length of the third side if the other two sides are 8 cm and 5 cm?

Back

The minimum length of the third side must be greater than 3 cm.

Front

What does it mean for a triangle to be 'not to scale'?

Back

'Not to scale' means that the lengths of the sides and angles are not represented proportionally in the diagram.

Front

If a triangle has sides of lengths 3 cm, 4 cm, and 5 cm, does it satisfy the Triangle Inequality Theorem?

Back

Yes, because 3 + 4 > 5, 3 + 5 > 4, and 4 + 5 > 3.

Front

What is the relationship between the angles and sides of a triangle?

Back

In a triangle, the largest angle is opposite the longest side, and the smallest angle is opposite the shortest side.

Front

If a triangle has two equal sides, what type of triangle is it?

Back

It is an isosceles triangle.

Front

What is the sum of the interior angles of a triangle?

Back

The sum of the interior angles of a triangle is always 180 degrees.