I dont remember how to rewrite formulas properly

What percent of the circle below is shaded?

When george started his current job, his employer told him that at the end of the first year, he would receive two vacation days. after each year worked, his number of vacation days will double up to five work weeks (25days) of payed vacation. how many vacation days will he have in 4 years

What is the circumference of a circle with an area of 50.24 cm²?