Question

Given triangle `∆ABC ~ ∆DEF` and `(AB)/(AC) = 2/5`, what is `DE` if `DF = 20`?

Answer 1

`DE=8`

Explanation:

If `DeltaABC and DeltaDEF` are similar, then `(AB)/(AC)=(DE)/(DF)`

Given `(AB)/(AC)=2/5, and DF=20`,

`=> (DE)/20 = 2/5`
`=> DE =20*2/5`
`=> DE=40/5=8`