Warm Up: pg. 8
Why are A, B, J, and G coplanar?
1-4
Segment Lengths
Objective: Calculate the length of line
segments, and portions of line
segments using the Segment
Addition Postulate
Segment Addition Postulate
If B is between A and C then AB + BC = AC
AC
A B C
AB BC
Put Simply: The whole is equal to the sum of its parts.
A word on notation…
AB vs. AB
Ex. 1: Find KN.
Ex. 2: Find MN, if KN = 26.
Ex. 3: Find MN, if KN = 26.
Ex. 4: B is between A & C. Solve for x and
find AB and BC. (A sketch is in order!!)
AB = x
BC = 2x + 1
AC = 22
Ex. 5: E is between D & F. Solve for y and
find DE, EF and DF.
DE = 3y - 4
EF = y + 2
DF = 2y + 8
Lesson Summary & Closing Thoughts:
What is the simple way, in words, to
remember the Segment Addition Postulate?
Homework: pg. 10