Angle Relationships and Triangles

Front

What are vertical angles?

Back

Vertical angles are the angles opposite each other when two lines intersect. They are always equal.

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

What are complementary angles?

Back

Complementary angles are two angles whose measures add up to 90 degrees.

Front

What are supplementary angles?

Back

Supplementary angles are two angles whose measures add up to 180 degrees.

Front

What is a transversal?

Back

A transversal is a line that intersects two or more lines at different points.

Front

If two parallel lines are cut by a transversal, what can be said about the alternate interior angles?

Back

Alternate interior angles are equal when two parallel lines are cut by a transversal.

Front

If angle 4 is 40 degrees, what is the measure of angle 2 if lines are parallel?

Back

Angle 2 is also 40 degrees because they are corresponding angles.

Front

What is the relationship between exterior angles and the two opposite interior angles in a triangle?

Back

The exterior angle of a triangle is equal to the sum of the two opposite interior angles.

Front

If angle 1 is 49 degrees, what is the measure of angle 3 if angle 1 and angle 3 are complementary?

Back

Angle 3 is 41 degrees because 90 - 49 = 41.

Front

What is the definition of an acute angle?

Back

An acute angle is an angle that measures less than 90 degrees.