L10/11 Segment Addition and Angle Bisector
Objective: We can use the pieces of a segment and angle to calculate the whole or other
piece.
Defns:
(b) 𝑅𝑆 = 6𝑥, 𝑆𝑇 = 12𝑥, 𝑅𝑇 = 90
Segment Length/Measure: A segment with
endpoints A and B is called _______ or ________
its length/measure is written as ________.
Something Obvious:
(c) 𝑅𝑆 = 3𝑥 + 1, 𝑆𝑇 = 5𝑥 + 2, 𝑅𝑇 = 67
Finding the Segment Measure
Ex1: Find the value of the variable and 𝑆𝑇 if S
between R and T.
Angle Bisectors
(a) 𝑅𝑆 = 17, 𝑆𝑇 = 2𝑎, 𝑅𝑇 = 20
Defns:
Angle Bisector: A line that divides an angle into
two congruent/equal angles.
Measuring an Angle:
Finding the Angle Measure
Ex1: 𝐵𝐷 bisect ∠𝐴𝐵𝐸 and 𝐵𝐹 bisects ∠𝐸𝐵𝐶.
(a) If 𝑚∠𝐸𝐵𝐶 = 50° and 𝑚∠𝐸𝐵𝐹 = 5𝑥 + 10, find
𝑚∠𝐸𝐵𝐹 and x.
(b) If 𝑚∠1 = 2𝑏 and 𝑚∠𝐴𝐵𝐸 = 6𝑏 − 52, find
𝑚∠1 and b.
(c) If 𝑚∠3 = 5𝑥 + 3 and 𝑚∠𝐹𝐵𝐶 = 3𝑥 + 11, find
𝑚∠𝐸𝐵𝐶 and x.