Answer:
a = 9
Step-by-step explanation:
For solve the problem we can use the Pythagorean theorem in this way
a^2 + (3√3)^2 = (6√3)^2
If we solve the equation we have
a^2 + 27 = 108
a^2 = 81
a = +/-9
we take only the the positive value because a length can’t be negative
a = 9
