FLASHCARD 2: Angles in Triangles

Front

What is an exterior angle in a triangle?

Back

An exterior angle is formed by one side of a triangle and the extension of an adjacent side. It is equal to the sum of the two opposite interior angles.

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.

Front

How do you find the measure of an unknown angle in a triangle?

Back

To find an unknown angle, subtract the sum of the known angles from 180 degrees.

Front

What is the relationship between an exterior angle and the interior angles of a triangle?

Back

An exterior angle is equal to the sum of the two non-adjacent interior angles.

Front

If one angle of a triangle measures 54 degrees, what is the maximum possible measure of the other two angles?

Back

The maximum possible measure of the other two angles combined is 126 degrees, since the total must equal 180 degrees.

Front

What is the measure of an angle if it is supplementary to a 31-degree angle?

Back

The measure of the angle is 149 degrees, since supplementary angles add up to 180 degrees.

Front

What is the measure of an angle if it is complementary to a 54-degree angle?

Back

The measure of the angle is 36 degrees, since complementary angles add up to 90 degrees.

Front

How do you determine if a triangle is acute, right, or obtuse based on its angles?

Back

A triangle is acute if all angles are less than 90 degrees, right if one angle is exactly 90 degrees, and obtuse if one angle is greater than 90 degrees.

Front

What is the formula for finding the measure of an angle in an isosceles triangle?

Back

In an isosceles triangle, the two base angles are equal, and the vertex angle can be found by subtracting the sum of the base angles from 180 degrees.

Front

What is the definition of a triangle?

Back

A triangle is a polygon with three edges and three vertices.