7.5 Triangle Proportionality Cut by Parallel Line
Side length ratios in a triangle cut by a line parallel to a base.
Note: Segment DE is parallel to segment BC.
As you move point A, what do you notice?
As you move point B, what do you notice?
As you move point C, what do you notice?
Which segments are proportional?
Explore the applet below, then answer the questions.
As you move segment XM, what do you notice?
As you move segment YN, what do you notice?
As you move segment ZO, what do you notice?
What segments are proportional? How do you know?
Solve for the missing variables.
x = _____.
y = _______
a = _____.
b = _____.
c = _____.
Solve for x.
x = _______.