Help me fast pls

What is the best approximation for the area of a circle with a radius of 4 m ? use 3.14 to approximate pi

1) you deposit $2,500 in an account that earns 4% simple interest. how much do you earn in eight years?

Amountain climber starts a climb at an elevation of 453 feet above sea level at his first rest stop he has climbed 162 feet and by his second rest stop he has climbed another 207 feet its getting late in the day so the climber starts his way down if the climber desends 285 feet how much does he need to ascend or descend to return to the original starting point