Answer:
A. Pentagon with side of 4 ft
Area of a polygon formula:
- A= (1/4) × n × s² × cot(π/n), where n-number of sides, s-side length
Applied to our pentagon:
- A = (1/4)×5×4²×cot(π/5) ≈ 27.5 ft²
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B. Octagon with apothem of 5 cm
Area of polygon:
- A = n × a² × tan(π/n), where n-number of sides, a- apothem
Applied to our octagon:
- A = 8×5²×tan(π/8) ≈ 82.8 cm²