Answer:
4 sqrt(3)
Explanation:
Since this is a right triangle, we can use the Pythagorean theorem
a^2 + b^2 = c^2
3^2 + (sqrt(39)^2 = c^2
9 + 39 = c^2
48 = c^2
Take the square root of each side
sqrt(48) = sqrt(c^2)
sqrt(16*3) = c
sqrt(16) sqrt(3) = c
4 sqrt(3) = c