Question

Solve similar triangles (advanced)

Answer 1

Answer:

  x = 9/4

Step-by-step explanation:

Locate point G on segment DE so that DG = 1 and GE = 4. CG is parallel to AD, so ΔCGE ~ ΔABC. Corresponding sides are proportional.

  AB/BC = CG/GE

  x/1 = 9/4

  x = 9/4

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Additional comment

Using the given triangles, you can write the proportion statement as ...

  (9+x)/x = 5/1

We judge this to take more steps to solve, so we prefer the method shown above.