Answer:
- x = 2 cm
- x = 17 cm
Step-by-step explanation:
You want the two possible values of x given the triangles in the figure are similar.
Assumption 1
We assume the similar triangles are ∆ABE ~ ∆ACD.
The corresponding sides are proportional, so we have ...
[tex]\dfrac{AB}{AE}=\dfrac{AC}{AD}\\\\\\\dfrac{10}{15}=\dfrac{10+x}{18}\\\\\\x=\dfrac{10\cdot18}{15}-10=2[/tex]
x = 2 cm
Assumption 2
We assume the similar triangles are ∆ABE ~ ∆ADC.
The corresponding sides are proportional, so we have ...
[tex]\dfrac{AB}{AE}=\dfrac{AD}{AC}\\\\\\\dfrac{10}{15}=\dfrac{18}{10+x}\\\\\\x=\dfrac{15\cdot18}{10}-10=17[/tex]
x = 17 cm