Find the hypotenuse of each isosceles right triangle when the legs are o the given measure. given = 5”

In any right triangle,
      (Hypotenuse)²  =  (one leg)²  +  (other leg)² .
In an isosceles right triangle, the legs have equal lengths, so   
       (Hypotenuse)²  =  (leg)²  +  (leg)² . 
       (Hypotenuse)²  =   2 (leg)² .
         Hypotenuse = √(2 leg²)
        Hypotenuse  =  leg √2 .
In this particular isosceles right triangle,
         Hypotenuse = 6 √2 cm.
                leg √2  =  6 √2
                leg       =  6  cm     

The answer is something i don’t know

It's like discovering the answer to a puzzle. the purpose in solving an equation is to find the value or values of the variable that makes it a true statement. any value of the variable that makes the equation true is called a solution to the equation.