Let L be an algebraic extension of K. Show that any algebraic closure of L is also an algebraic closure of K.

Question

1. A field F is said to be algebraically closed if every algebraic extension E/F is trivial, i.e., E=F.
2. so according to this theorem any extension L of K will be equal L=K. of the algebraic closure of L is also an algebraic closure of K.

How to prove the first part that algebraic extension of an algebraically closed field is equal?