Answer:
8.5
Explanation:
area of a rhomus = (1/2)(product of its diagonals)
let the other diagonal be a
(1/2)(15a) = 60
15a= 120
a = 8
So let's find the hypotenuse of one of the right-angled triangles formed by the intersection of its diagonals
base = 4, height = 7.5
if h is the hypotenuse,
h^2 = 4^2 + 7.5^2
h = 8.5