Answer:
8.......................
Step-by-step explanation:
It's clear that the figure is rhombus (because diagonals make right angle).
Rhombus area formula: (AC×BD)÷2
So if we have area and one diagonal then it's easy to find another diagonal.
S=AC×BD÷2
14.5×BD÷2=58
14.5BD=58×2
14.5BD=116
BD=116÷14.5
BD=8
