Answer:
h = 9
Explanation:
You can use the Pythagorean theorem to solve this. Consider each half of the main triangle their own triangles.
h = a
a^2 + b^2 = c^2
or
a^2 = c^2 - b^2
a^2 = 10^2 - 5^2
a^2 = 100 - 25
a^2 = 75
a = √75
a = 8.66, or 9
h = 9 (when rounded)