Transcript Chapter 8 Lesson 5 - Mrs.Lemons Geometry

Chapter 8 Lesson 5
Objective: To use the
Side-Splitter theorem.
Theorem 8-4
Side-Splitter Theorem
If a line is parallel to one side of a
triangle and intersects the other two
sides, then it divides those sides
proportionally.
XR YS

RQ SQ
Example 1: Using the Side-Splitter Theorem
Solve for x.
TS TU

SR UV
x
5
16

10
10x  80
x 8
Example 2: Using the Side-Splitter Theorem
Use the Side-Splitter Theorem to find
the value of x.
x  1. 5
5

x
2. 5
2.5(x  1.5)  5x
2.5x  3.75  5x
3.75  2.5x
1.5  x
Corollary to Theorem 8-4
If three parallel lines intersect two
transversals, then the segments
intercepted on the transversals are
proportional.
c
a
b = d
Example 3: Real World Connection
Sail makers sometimes use a computer to create a
pattern for a sail. After they cut out the panels of
the sail, they sew them together to form the sail.
The edges of the panels in the sail at the right are
parallel. Find the lengths x and y.
2
1. 7

x 1. 7
Side-Splitter Theorem
x 2
y
3

2 1. 7
5.1  2y
2.55  y
Corollary to the
Side-Splitter Theorem
Assignment
Pg. 448
#1-10;25,26,31,
33, 48-50