A.C.
At that age, she doesn't have much if any emotional control (this is normal) and no way to express her feelings. Use positive statements like ("we keep our hands to ourselves" or "we keep our hands down" instead of "no hitting" because they can more easily do a positive thing than stop doing a negative thing). Walk away, and/or put her toys in time out if she throws them. Redirect her with something else. And most importantly, give her words: "I know you're angry because you want to keep playing." "I know you're frustrated you can't make your toy work the right way." "I know you're mad at mommy." Then explain "but we keep our hands to ourselves" or "hitting hurts people/throwing toys can hurt people."
Sometimes, I get up and walk away from it (for my sake and to take away the attention). I do try to redirect to more positive play/action. And sometimes I say, after giving her words for what she's feeling, "Mommy and X are both upset. How about a hug?" or "How about we sit and read your favorite book?" etc.