Geo 2.3 Triangle Sum & Exterior Angle Theorems

Front

What is the Triangle Sum Theorem?

Back

The Triangle Sum Theorem states that the sum of the interior angles of a triangle is always 180 degrees.

Front

Define Same-side Interior Angles.

Back

Same-side Interior Angles are pairs of angles that lie on the same side of a transversal and between two parallel lines.

Front

What are Corresponding Angles?

Back

Corresponding Angles are pairs of angles that are in the same position on two parallel lines in relation to a transversal.

Front

What are Vertical Angles?

Back

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

Front

What are Alternate Interior Angles?

Back

Alternate Interior Angles are pairs of angles that lie between two parallel lines but on opposite sides of a transversal.

Front

If one angle of a triangle is 60 degrees and another is 70 degrees, what is the measure of the third angle?

Back

The third angle measures 50 degrees (180 - 60 - 70 = 50).

Front

Solve for x if the angles are 2x and 3x in a triangle.

Back

x = 30 degrees (2x + 3x + 180 = 180, so 5x = 180, x = 36).

Front

What is the measure of an exterior angle of a triangle?

Back

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

Front

If angle A is 40 degrees and angle B is 60 degrees, what is the measure of the exterior angle at vertex C?

Back

The exterior angle at vertex C measures 100 degrees (40 + 60 = 100).

Front

What is the relationship between the angles in a linear pair?

Back

Angles in a linear pair are supplementary, meaning they add up to 180 degrees.