A square postage stamp has area1,190mm^2. About how long is each side?

Do you mind if you guys me with this question i’m on number 8

Apool measures 100 meters by 100 meters a toddler inside the pool and trows a ball 60 centimeters from one edge of the pool. how far is the ball from the opposite edge of the pool

You draw a card at random from a deck that contains 33 black cards and 77 red cards.