
1.  Two lines that intersect to form a right angle are ________. 
3.  A type of proof written as numbered statements and reasons that show the logical order of an argument. 
5.  Two lines that do not intersect and are not coplanar. 
9.  ________ angles are two angles that are formed by two lines and a transversal and occupy corresponding positions. 
10.  Two adjacent angles whose noncommon sides are opposite rays. 
11.  Alternate ________ angles are two angles that are formed by two lines and a transversal and that lie outside the two lines on opposite sides if the transversal. 


2.  The sum of the measures of an angle and its ________ is 90°. 
4.  ________ interior angles are two angles that are formed by two lines and a transversal and that lie between the two lines on the same side of the transversal. 
5.  The sum of the measures of an angle and its ________ is 180°. 
6.  Consecutive interior angles are also called ________ interior angles. 
7.  A type of proof that uses arrows to show the flow of a logical argument. Statements are connected by arrows to show how each statement comes from the ones before it, and each reason is written below the statement it justifies. 
8.  Alternate ________ angles are two angles that are formed by two lines and a transversal and that lie between the two lines on opposite sides of the transversal. 