Download Chapter 2-6

Chapter 2-6
Theorems; Segments and Lines
Theorem 2.7: Common Segment Theorem
1. If line AB is congruent to line CD then line AC is congruent to line BD
2. If line AC is congruent to line BD then line AB is congruent to line CD
Methods of Proving Two Segments are Congruent
1. Prove that their measures are equal using the segment addition postulate or
properties of equality.
2. Prove that each segment is congruent to a third segment.
3. Prove that they are the two parts of a bisected segment.
4. Prove that they are sides of a triangle given to be isosceles or equilateral.
5. Prove that they are formed by adding or subtracting a common segment.
Theorem 2.8
If two lines form congruent adjacent angles, then they are perpendicular.
Method of Proving Two Lines Perpendicular
1. Prove the lines intersect to form a right angle.
2. Prove that the lines intersect to form congruent angles.
Theorem 2.9
Only one perpendicular can be drawn from a point to a line.