Flashcards in Lines And Angles Deck (19):
What kinds of angles are there?
What is an acute angle?
An angle that is greater than 0° but smaller than 90°
What is a right angle?
An angle of 90°
What is an obtuse angle?
It is greater than 90° but smaller than 180°
What is a straight angle?
An angle of 180°
What is a reflex angle?
Greater than 180° but smaller than 360°
What is a revolution?
An angle of 360°
What are adjacent angles?
Two angles with a common vertex (corner) that lie next to each other.
What are complementary angles?
Angles with a sum of 90°
What are supplementary angles?
Angles that add up to 180°
What are angles on a straight line?
They are supplementary i.e they add up to 180°
What are vertically opposite angles?
They are angles made up of the same two lines. They are equal.
What are angles around a point?
They are angles that surround a common vertex. They add up to 360°
What are the three parallel line theorems?
What are corresponding angles?
When the parallel lines that make up two angles form an 'F' shape, those two angles are equal.
What are alternate angles?
When the parallel lines that make up two angles form a 'Z' shape, those two angles are equal.
What are co-interior angles?
When the parallel lines that make up two angles form a 'U' shape, those two angles are supplementary.
What is important to remember when using parallel line theorems?
Always make sure that the lines that you are using are actually parallel
Always state the parallel lines that you used in your reason