Joey's Pizza Palace sells four sizes of pizza. The mini pizza has a 6-inch diameter, and the medium pizza has a diameter twice that of the mini pizza. How many more square inches of pizza are there in the medium than in the mini pizza? Round your answer to the nearest tenth.

Question

campbell_st · Answer

well the area of a circle is 

$$A = \pi r^2$$

where r = radius

the mini has a radius of r = 3 inches

so the medium has a radius of 6 inches

find the area of both pizzas 

then the area difference is

Area Difference = Area of Medium - Area of Mini

mathmale · Answer

Gracie:  Campbell found the radii of those two different pizzas be dividing the respective diameters by 2.  His (or her) proposed formula for finding the difference in the areas is right on.  Can you finish this problem?