Answer:
DE = 4.24
Explanation:
The diagram is not shown; However, the question can still be solved without the diagram.
Having said that,.
Given that
DF = EF = 3
This implies that DE is the hypothenus and will be solved using Pythagoras theorem.
DE² = EF² + DF²
Substitute 3 for EF and DF
DE² = 3² + 3²
DE² = 9 + 9
DE² = 18
Take Square Root of both sides
DE = √18
DE = 4.242640687119285
DE = 4.24 (Approximated)