Answer:
27 inches
Step-by-step explanation:
We can use The Pythagorean theorem
a^2+b^2 = c^2 where a and b are the legs and c is the hypotenuse
21.6 ^2 + 16.2^2 = c^2
466.56+262.44 = c^2
729 = c^2
Taking the square root of each side
sqrt(729) = sqrt(c^2)
27 = c