To calculate the amount of wrapping paper needed, we need to find the surface area of the triangular prism.
A triangular prism has 5 faces - 2 triangular faces and 3 rectangular faces.
Let's assume the triangular prism has side lengths a, b, and c.
The surface area of a triangular prism can be calculated using the formula:
SA = 2 * (base area) + (perimeter of base) * (height)
First, let's calculate the base area of the triangular faces:
Base area = (1/2) * base * height
Next, let's calculate the perimeter of the base:
Perimeter of base = a + b + c
Now, let's calculate the height of the triangular prism:
Height = h
Plugging in the values and calculating:
Base area = (1/2) * (a * h) = 0.5ah
Perimeter of base = a + b + c
Height = h
Surface Area = 2 * (base area) + (perimeter of base) * (height)
Surface Area = 2 * 0.5ah + (a + b + c) * h
Surface Area = ah + bh + ch
Assuming the dimensions of the triangular prism are in whole numbers, the amount of wrapping paper needed will be:
2 * (11 + 9 + 7) + (11 * 9 + 9 * 7 + 11 * 7)
2 * 27 + 99 + 63 + 77
54 + 99 + 63 + 77
273 square units
So, 273 square units of wrapping paper is needed to wrap the toy.