Question 1005205
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There are two solutions.


One is


h = {{{sqrt(10^2-8^2)}}} + {{{10}}} = 6 + 10 = 16 cm.


The second is 


h = {{{10}}} - {{{sqrt(10^2-8^2)}}} = 10 - 6 = 4 cm.


Make a sketch, and everything will be clear to you.