Answer:
The missing side is 10.25
Step-by-step explanation:
Step 1: Use Pythagorean Theorem
[tex]11^{2} = 3.9^{2} + x^{2} \\121 = 15.21 + x^{2}\\121 - 15.21 = x^{2} \\105.79 = x^{2} \\\sqrt{105.79} = \sqrt{x^{2} } \\x = 10.285[/tex]
Therefore the missing side is 10.285
