There are a few ways to make a shape a specific size in Illustrator. The first way is to use the Size property. The Size property allows you to control the size of an object. You can control the size of an object by setting its Width, Height, and Margin properties. The second way is to use the Format property. The Format property allows you to change the format of an object. You can change the format of an object by setting its Format property and its Value property. The third way is to use the Selection command. The Selection command allows you to select one or more objects and change their sizes.