Question

What is length of Ef?
A.10
B.15
C.20
D.v200
E.v300
F.v500

Answer 1

Answer:

Answer E is correct

Step-by-step explanation:

Let the Length of EF be x

Use PYTHAGORAS theorem to find the length of EF

EF² + DF² = DE²

${x}^{2} + {10}^{2} = {20}^{2} \\ {x}^{2} + 100 = 400 \\ {x}^{2} = 400 - 100 \\ {x}^{2} = 300 \\ x = \sqrt{300}$

So,

$EF = \sqrt{300}$

Hope this helps you.

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