Jon S. answered 05/09/21
Patient and Knowledgeable Math and English Tutor
The slant height, height and one half of the length of a side form a right triangle with the slant height as the hypotenuse, so by the Pythagorean Theorem:
half length of side ^2 + height^2 = slant height^2
8^2 + height^2 = 10^2
height = 6 cm