Triangles: Classification, Angles, Sides Lengths

Front

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

Back

Yes, these lengths satisfy the triangle inequality theorem.

Front

Equilateral triangles have sides that are all equal?

Back

True, all sides of an equilateral triangle are equal.

Front

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

Back

12, because it satisfies the triangle inequality theorem.

Front

Find the measure of the missing angle if two angles are 60° and 70°.

Back

50°, because the sum of angles in a triangle is 180°.

Front

Do side lengths of 4, 4, 4 form a triangle?

Back

True, they form an equilateral triangle.

Front

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

Back

180°.

Front

What type of triangle has one angle greater than 90°?

Back

Obtuse triangle.

Front

What is the Pythagorean theorem?

Back

In a right triangle, a² + b² = c², where c is the hypotenuse.

Front

What is a scalene triangle?

Back

A triangle with all sides of different lengths.

Front

What is the definition of a right triangle?

Back

A triangle that has one angle measuring 90°.