To find the area of one of the triangular shelves, we will use the formula for the area of a triangle given two sides and the included angle:
\[ \text{Area} = \frac{1}{2}ab\sin(C) \]
where \(a\) and \(b\) are the lengths of the two sides, and \(C\) is the included angle.
Given:
- \(a = 22\) inches
- \(b = 35\) inches
- \(C = 87^\circ\)
First, we need to calculate \(\sin(87^\circ)\).
Using a calculator, \[ \sin(87^\circ) \approx 0.998 \]
Now, we can substitute these values into the area formula:
\[ \text{Area} = \frac{1}{2} \times 22 \times 35 \times \sin(87^\circ) \] \[ \text{Area} = \frac{1}{2} \times 22 \times 35 \times 0.998 \] \[ \text{Area} \approx \frac{1}{2} \times 22 \times 35 \times 0.998 \approx 385.3 \text{ square inches} \]
Now we need to calculate the total area for all three shelves:
\[ \text{Total Area} = 3 \times 385.3 \approx 1155.9 \text{ square inches} \]
Rounding to the nearest square inch:
\[ \text{Total Area} \approx 1156 \text{ square inches} \]
Looking at the responses provided, it seems that the answer is closest to:
1,153 inches²
Therefore, the correct amount of shelving paper she needs to buy is:
1,153 inches²