When baking a cake you can choose between a round pan with a 9 in. diameter and a 8 in. times 11 in. rectangular pan?

Question says that there are two type of pans.

First pan has diameter of 9 inches.

Second pan has dimension 8 inches by 11 inches. Which means second pan is rectangular.

It seems you missed few parts of the question like what we have to do with it. I searched for similar question on internet and found that they are finding surface area of the both pans so i will tell you how to find that.

Radius of the circular pan = diameter/2 = 9/2 = 4.5 inches

Then surface area of the first (circular) pan = \pi r^2 = 3.14 *4.5^2 = 63.585 square inches.

Now surface area of second (rectangular) pan is given by formula of area of rectangle

Area = Length * width = 8*11= 88 square inches.