5.1-5.5 Flashcard Review (Triangle Angles and Sides)

Front

What is the sum of the angles in a triangle?

Back

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

Front

What is the Triangle Inequality Theorem?

Back

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

Front

Can a triangle have angles measuring 90°, 45°, and 45°?

Back

Yes, this is a valid triangle as the sum is 180°.

Front

If one angle of a triangle is 110°, what is the maximum possible measure of the other two angles?

Back

The maximum possible measure of the other two angles is 70° (since 180° - 110° = 70°).

Front

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

Back

In a triangle, the larger the angle, the longer the opposite side.

Front

If a triangle has sides of lengths 3, 4, and 5, is it a right triangle?

Back

Yes, it is a right triangle because it satisfies the Pythagorean theorem: 3² + 4² = 5².

Front

What is the measure of the third angle if two angles of a triangle are 30° and 60°?

Back

The third angle measures 90° (180° - 30° - 60° = 90°).

Front

Can a triangle have sides measuring 3, 4, and 9?

Back

No, this is not possible because 3 + 4 is not greater than 9.

Front

What is an obtuse triangle?

Back

An obtuse triangle is a triangle that has one angle measuring more than 90°.

Front

What is an acute triangle?

Back

An acute triangle is a triangle where all three angles are less than 90°.