1. If equal quantities are added to equal quantities, the sums are equal.
Addition Postulate:
2 cm
7 cm A B C D E F G H
Geometry Lesson: Addition/Subtraction Postulates

2. Subtraction Postulate:
If equal quantities are subtracted from equal quantities, the differences are equal.
Subtraction Postulate:
2 cm
7 cm A B C D E F G H
Geometry Lesson: Addition/Subtraction Postulates

3. Given: Ex 1: Prove: A D E F C B Statements Reasons 1) 2) 3) 4) 5) 6)
Addition Postulate
Partition Postulate
Partition Postulate
Substitution Postulate
Geometry Lesson: Addition/Subtraction Postulates

4. Given: Ex 2: Prove: D A C E B 1 3 4 2 Statements Reasons 1) 2) 3) 4)5) 6)
Given
Given
Partition Postulate
Partition Postulate
Substitution Postulate
Subtraction Postulate (5,2)
Geometry Lesson: Addition/Subtraction Postulates