Final answer:
The new surface area of a square pyramid when its dimensions are multiplied by 1/3 is calculated by squaring the scale factor (1/3) and multiplying it with the original surface area. In this case, the new surface area is 121 in².
Step-by-step explanation:
When the dimensions of a square pyramid are multiplied by 1/3, each linear dimension of the pyramid becomes one-third of its original size. Since surface area is a two-dimensional measure (length × width), when you scale down each dimension by a factor of 1/3, the new surface area will be the square of that scale factor times the original area. The surface area is proportional to the square of the scaling factor because area is calculated using two dimensions.
The original surface area is 1,089 in². To find the new surface area, we use the scale factor squared: (1/3) ² = 1/9. We then multiply the original surface area by this factor:
New Surface Area = Original Surface Area × (Scale Factor)²
New Surface Area = 1,089 in² × 1/9
New Surface Area = 1,089 in² / 9
New Surface Area = 121 in²
Therefore, the new surface area of the square pyramid when the dimensions are multiplied by 1/3 will be 121 in².