Use pythagoras since it has a right angle ma boi

the formula for that is a^2 + b^2 + c^2

therefore 2sqrt(3)^2 - sqrt(3)^2 = (the missing side length)^2

2sqrt(3)^2 = 6 and sqrt(3)^2 =3

6- 3 = 2

bu then you have to sqrt your answer which means you have__ sqrt 2__ at the end