To find the probability that the keys have landed within the forest, we first need to determine the area of the forest within the specified trapezoid.
According to the information provided:
- The total area of the trapezoid is \(35 \text{ acres} + 20 \text{ acres} + 45 \text{ acres} = 100 \text{ acres}\).
- The shaded areas (forest), which are represented by the top and bottom sections of the trapezoid, comprise \(35 \text{ acres} + 45 \text{ acres} = 80 \text{ acres}\).
Now we can calculate the probability that the keys landed in the forest:
\[ \text{Probability (keys in forest)} = \frac{\text{Area of forest}}{\text{Total area}} = \frac{80 \text{ acres}}{100 \text{ acres}} = 0.8 \]
Thus, the probability that the keys have landed within the forest is \(0.8\).
The correct answer is \(0.8\).