Question

Find the surface area of a rectangular pyramid with these measurements: l
= 8 cm, w
= 4 cm, and h
= 2 cm. Express your answer as a decimal rounded to the nearest hundredth.(1 point)
___ cm2

Answer 1

Base area = l·w = 8·4 = 32 cm².

Slant heights:
- along the 8-cm side: s1 = sqrt(h² + (w/2)²) = sqrt(2² + 2²) = sqrt(8) = 2√2 ≈ 2.82843
- along the 4-cm side: s2 = sqrt(h² + (l/2)²) = sqrt(2² + 4²) = sqrt(20) = 2√5 ≈ 4.47214

Lateral area = l·s1 + w·s2 = 8·2.82843 + 4·4.47214 ≈ 40.51596

Total surface area = 32 + 40.51596 ≈ 72.51596 ≈ 72.52 cm²

Answer: 72.52 cm².