Use exponents to write 9,800,100 in expanded form

The figures below are made out of circles, semicircles, quarter circles, and a square. find the area and the perimeter of each figure and give your answers as a completely simplified exact value in terms of π (no approximations).

2.5 milligrams is equivalent to how many grams

Anyone? 15m is what percent of 60m; 3m; 30m; 1.5 km?