Answer:
13√(2) = x
Explanation:
The given is an isosceles triangle so the two side lenghts are same (13 units)
in right triangles the square lenght of the hypotenus is equal to sum of two side's square lenght
13^2 + 13^2 = x^2
169 + 169 = x^2
338 = x^2
13√(2) = x