$\eqalign{
  & 10{}^2 - {x^2} = {9^2} - {(9 - x)^2}  \cr
  & x = 5\frac{5}{9}  \cr
  & h = 2\frac{2}{9}\sqrt {14}   \cr
  & O = 103\frac{7}{9}\sqrt {14}  \cr} $