Download Theorem 7-3: Triangle Proportionality Theorem If a line

GEOMETRY/TRIGONOMETRY 2
Name _______________________
Theorem 7-3: Triangle Proportionality Theorem
If a line _________________ to one side of a triangle intersects the other two sides,
then it divides those sides _________________________.
The properties of proportions allows the Triangle Proportionality Theorem to justify many
equivalent proportions. Some are given below:
DG

GE

GE

DE

DG

DE

GE

HF

DG

DH

SPECIAL NOTE:
If you are given the bottom of the triangles (the || sides), you must use the
whole sides of the triangles to form the proportion. See problem #4
Corollary: Triangle
If three _________________ lines intersect two transversals, then they divide the
transversals _________________________.
Theorem 7-4: Triangle Angle-Bisector Theorem
If a ray _________________ an angle of a triangle, then it divides the opposite sides into
segments _________________________ to the other two sides.
Use the Triangle Proportionality Theorem to find the value of x.
1) x = _______
2) x = _______
3) x = _______
4) x = _______
5) x = _______
6) x = _______
Use the corollary to find the value of x.
7) x = _______
8) x = _______
Use the Triangle Angle-Bisector Theorem to find the value of x.
9) x = _______
10) x = _______