Angles and Triangles

Front

What are vertical angles?

Back

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

Front

What are corresponding angles?

Back

Corresponding angles are the angles that are in the same position at each intersection where a straight line crosses two others. They are equal when the lines are parallel.

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 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 the measure of an unknown angle in a triangle, subtract the sum of the known angles from 180 degrees.

Front

What is a transversal?

Back

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

Front

What is the relationship between alternate interior angles when two parallel lines are cut by a transversal?

Back

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

Front

What is the relationship between same-side interior angles when two parallel lines are cut by a transversal?

Back

Same-side interior angles are supplementary when two parallel lines are cut by a transversal.

Front

If angle 4 is 70 degrees, what is the measure of angle 2 if lines are parallel?

Back

Angle 2 is also 70 degrees because they are corresponding angles.