Name: _______________________
Similar Triangles: Day 2
Date: ____ Period:____
Ms. Anderle
Similar Triangles: Day 2
Many problems involving similar triangles have one triangle ON TOP OF another
triangle.
Since DE is marked parallel to AC, we know
that we have <BDE equal in measure to <DAC
(corresponding angles). <B is shared by both
triangles (reflexive). Therefore, ∆BDE ~
∆BAC.
In order to attack a problem like this, we must
separate the two triangles. We must use the
FULL sides of the triangles when dealing with
this problem. Do not use DA or EC since they are not sides of the triangles!!!
Examples:
1)
Find BE:
2)
Find EC:
3)
Find x:
4)
DB = 5, AD = x, DE = x, and AC = 10.
a) Find the value of x:
b) Find the ratio of similitude:
5)
DB = 3, DA = x, DE = x, and AC = 6
a) Find the value of x:
b) Find the scale factor:
6)
Find BE and the ratio of similitude: