The diagram shows a circle with radius 2.1 cm inside a square. The circle touches the sides of the square.
Work out the shaded area.
Give your answer correct to 3 significant figures.

Abari owns 100 shares of stock a and 45 shares of stock b. for the past month, his stocks have been fluctuating inversely. stock a decreased by m cents per share and stock b increased by n cents per share. which equation can be used to find the total change in value of jabari's shares per month?