Angle Addition Flashcard Review

Front

What is angle addition?

Back

Angle addition is a principle in geometry that states if two angles are adjacent (next to each other), the measure of the larger angle is the sum of the measures of the two smaller angles.

Front

What is the measure of a right angle?

Back

A right angle measures 90 degrees.

Front

What is the measure of a straight angle?

Back

A straight angle measures 180 degrees.

Front

What is the sum of angles in a triangle?

Back

The sum of the angles in a triangle is always 180 degrees.

Front

If ∠WST = 140°, what is the measure of the adjacent angle ∠XST if they form a linear pair?

Back

∠XST = 180° - 140° = 40°.

Front

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

Back

To find an unknown angle in a triangle, use the formula: Unknown angle = 180° - (sum of the other two angles).

Front

What does it mean for angles to be complementary?

Back

Two angles are complementary if their measures add up to 90 degrees.

Front

What does it mean for angles to be supplementary?

Back

Two angles are supplementary if their measures add up to 180 degrees.

Front

If ∠ABC = 60° and ∠ABD = 30°, what is the measure of ∠D?

Back

∠D = ∠ABC + ∠ABD = 60° + 30° = 90°.

Front

What is the relationship between vertical angles?

Back

Vertical angles are equal; when two lines intersect, the opposite angles formed are equal.