Answer:
AB = 7[tex]\sqrt{2}[/tex]
Step-by-step explanation:
Using Pythagoras' identity on the right triangle.
The square on the hypotenuse is equal to the sum of the squares on the other 2 sides, that is
x² = 7² + 7² = 49 + 49 = 98 ( take the square root of both sides )
x = [tex]\sqrt{98}[/tex] = [tex]\sqrt{49(2)}[/tex] = [tex]\sqrt{49}[/tex] × [tex]\sqrt{2}[/tex] = 7[tex]\sqrt{2}[/tex]