Geometry Flashcards

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

Answer: 180 degrees

A fundamental principle in Euclidean geometry states that the sum of the interior angles of any triangle is always 180 degrees. This property holds true for all types of triangles, regardless of their side lengths or angle measures. It is a basic rule used in countless geometric calculations.

In a right triangle, the side opposite the right angle is called the:

Answer: Hypotenuse

In a right triangle, the side directly opposite the 90-degree angle is known as the hypotenuse. It is always the longest side of the right triangle. The other two sides, which form the right angle, are called legs.

What type of triangle has all three sides of different lengths?

Answer: Scalene

A scalene triangle is defined by having all three of its sides of different lengths. Consequently, all three of its interior angles will also have different measures. This distinguishes it from equilateral (all sides equal) and isosceles (two sides equal) triangles.

Which of the following is true about the angles in an equilateral triangle?

Answer: All angles are 60 degrees

An equilateral triangle is characterized by having all three sides of equal length. As a direct consequence of this, all three interior angles are also equal. Since the sum of angles in any triangle is 180 degrees, each angle in an equilateral triangle must measure 60 degrees (180 / 3 = 60).

Which of the following is a property of similar triangles?

Answer: They have proportional corresponding side lengths and equal corresponding angles

Similar triangles are triangles that have the same shape but not necessarily the same size. This means their corresponding angles are equal, and the lengths of their corresponding sides are in proportion. This proportionality is key to understanding their relationship.