Answer:
I am a king who's good at measuring stuff.
To you, rude would I never be, though I flag my tongue for all to see. What am I?
I turn around once. What is out will not get in. I turn around again. What is in will not get out.
A little pool with two layers of wall around it. One white and soft and the other dark and hard, amidst a light brown grassy lawn with an outline of a green grass. What am I?
I'm really blue but when you see me I'm red. You don't see me too often. I'm there for you if you're hurt.
As round as an apple. As deep as a cup. All the king's horses can't pull it up.