Acylinder has a radius of 30ft and a height of 19ft. what is the exact surface area of the cylinder

We just started the introduction into circles and i have no idea how to do this.

The half-life of a certain material is 0.002 second. approximately how much of a 14-gram sample will be left after 0.004 second? a. 12 grams b. 3.5 grams c. 0.06 gram d. 7 grams

The perimeter of the rectangle is 120 feet. if the length of the rectangle is ten feet more than the width ,what are the dimensions (length and width) of the rectangle?