PLS PLS PLS PLS HELP

The diagonals of a rhombus are 12 inch and 16 inch long, the length of a side of a rhombus is 10 inch, what is the height of the rhombus

I'm terrible at math any here is appreciated.

Which of the following is the equation that says that the product of a number and ten is equal to 20 percent of that number ? a) 10n= 2.0n b) 10+n=.20n c) n+ .20n=10 d) 10n=0.20n