Answer:
x = 6 *[tex]\sqrt{10}[/tex]
Step-by-step explanation:
I assume x is the diagonal. length
if so here it goes:
the base length is 18
the height of the triangle should be ... 13 - 7 = 6
so hypotenuse = root ( 18^2 + 6^2) = root(324 + 36) = root(360) = 6root(10)
