Pizzas are sized by diameter. What percent increase in area results if Chantel's pizza increases from an 8-inch pizza to a 12-inch pizza?
+2668 Original pizza: \(4 ^2 \pi = 16 \pi\)
New pizza: \(6^2 \pi = 36 \pi\)
So, \(36 \div 16 = 2.25 = 225\text{%}\). But, recall that we are looking for the increase, so we subtract 100, to find that it is a \(\color{brown}\boxed{125 \text{%}} \) increase.
+1164 An 8-inch pizza has a radius of 4 inches.
A 12-inch pizza has a radius of 6 inches.
Area of first pizza: \(\pi r^2\)\(= 16\pi\)
Area of second pizza: \(\pi r^2=36\pi\)
Calculation of percentage: \(\frac{36-16}{16} \times 100 = 125%\)%
Therefore, the area is increased by \(125\)%
