For number 1, add the sides of the triangle. They are all given. The answer is 19.
For number 2, you use the formula for circumference, 2 times pi times radius. The answer is 43.96.
For number 3, I assume that 5 is half of one side. You would double 5 to get ten and multiply it by four, since there are four sides in a square. The answer is 40.
For number 4, you would multiply 5 times pi, but don't solve it. ( since the directions are to leave the answer in terms of pi) The answer is 5 pi.
For number 5, add all the sides together like number 1. The answer is 18.