1. **State the problem:** Find the area of a regular pentagon with an apothem of 5 units.
2. **Formula for the area of a regular polygon:**
$$\text{Area} = \frac{1}{2} \times \text{Perimeter} \times \text{Apothem}$$
3. **Important rules:**
- The apothem is the perpendicular distance from the center to a side.
- For a regular pentagon, the number of sides $n = 5$.
- To find the perimeter, we need the length of one side.
4. **Find the side length:**
The apothem $a$ relates to the side length $s$ by the formula:
$$a = \frac{s}{2 \tan(\pi/n)}$$
Rearranged to solve for $s$:
$$s = 2a \tan\left(\frac{\pi}{n}\right)$$
Substitute $a=5$ and $n=5$:
$$s = 2 \times 5 \times \tan\left(\frac{\pi}{5}\right) = 10 \times \tan\left(36^\circ\right)$$
Calculate $\tan(36^\circ) \approx 0.7265$:
$$s \approx 10 \times 0.7265 = 7.265$$
5. **Calculate the perimeter:**
$$P = n \times s = 5 \times 7.265 = 36.325$$
6. **Calculate the area:**
$$\text{Area} = \frac{1}{2} \times P \times a = \frac{1}{2} \times 36.325 \times 5 = 90.8125$$
7. **Round to nearest hundredth:**
$$\text{Area} \approx 90.81$$
**Final answer:** The area of the regular pentagon is approximately $90.81$ square units.
Pentagon Area 4B2727
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