Respuesta :

Answer:

x could be 9.2, 10 or 10.8.

Explanation:

If the triangle to be formed would be an isosceles, then:

DE = x = 10.

If the triangle is a right angled with CD = 10 as the hypotenuse. Applying Pythagoras theorem, we have:

[tex]10^{2}[/tex]  =  [tex]x^{2}[/tex]  + [tex]4^{2}[/tex]

100 = [tex]x^{2}[/tex] + 16

100 - 16 = [tex]x^{2}[/tex]

[tex]x^{2}[/tex] = 84

x = [tex]\sqrt{84}[/tex]

 = 9.1652

  ≅ 9.2

If the triangle is a right angled with DE = x as the hypotenuse, then:

 [tex]x^{2}[/tex]   =  [tex]10^{2}[/tex] + [tex]4^{2}[/tex]

       = 100 + 16

       = 116

x = [tex]\sqrt{116}[/tex]

   = 10.7703

x = 10.8