Calculating DE on this right triangle?

Question

anonymous · Answer

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campbell_st · Answer

ok... this problem uses similar triangles and the common side GE.... 


so looking at triangles 

DGE and GFE

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looking at the side ratios of triangle I to triangle II you have 

$$\frac{3}{GE} = \frac{GE}{8}$$

so $$EG^2 = 24$$

after cross multiplying 

now use pythagoras's theorem on triangle DGE to find DE

$$DE^2 = DG^2 + EG^2$$

you already have EG^2 

so 

$$DE^2 = 3^2 + 24$$

I'll leave you to finish it.

campbell_st · Answer

how about sqrt of 33

anonymous · Answer

15 was for a different question, sorry. I'm still trying to solve this one, almost got it.

anonymous · Answer

And I got 33. So thankyou!

campbell_st · Answer

hope it helps... its a tough question