A medium size pizza at Ristorante Porcupine is 10 inches in diameter. A large pizza is 21 inches in diameter. What percent larger is the area of a large pizza?
Express your answer to the nearest whole percent.
So I know that the area of the medium is 5pi and the bigger is 10.5pi but what do I do now?
Let $A_L$ and $A_M$ denote the areas of large and medium pizzas, then $$ \frac{A_L}{A_M} = \frac{\pi (21/2)^2}{\pi (10/2)^2} = \frac{21^2}{100} = 1 + \frac{?}{100}, $$ can you now complete the problem?