6.6 – Use Proportionality Theorems

Goal: You will use proportions with a triangle or parallel lines.

proportionallyproportionally

other sideother side

*Side not being touched by line

Determine if lines are parallelDetermine if lines are parallel

Example 3: Example 4:

Determine if // . Determine if // .

AEBD QT RS

Find x.

VXXZ

proportionallyproportionally

proportionalproportionalCABC

Use theorem 6.6Use theorem 6.6

Example 3:

A farmer’s land is divided by a newly constructed interstate. The distances are shown in meters. Find the distance CA between the north and south border of the farmer’s land.

Example 4:

Find AB.

Use theorem 6.6Use theorem 6.6

Use theorem 6.7Use theorem 6.7

Example 5:

In the diagram, . Use the given side lengths to find DG.

DEG GEF

Use theorem 6.7Use theorem 6.7

Example 6:

Find AB.