9514 1404 393
Answer:
- ornament area = 379.8 cm²
- paint needed: 114 bottles
Explanation:
The surface area of one cone with slant height s and radius r is ...
SA = πr² +πrs = πr(r+s)
For the cone that is half an ornament, the surface area is ...
SA = (3.14)(4.2 cm)(4.2 cm + 10.2 cm) = 189.9072 cm²
The area of one ornament is the area of two cones:
one ornament area = 2×189.9072 cm² ≈ 379.8 cm²
60 ornaments will be 120 cones, so will have a total surface area of ...
total area = 120(189.9072 cm²) = 22,788.864 cm²
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If one bottle of paint will cover 201 cm², then the number of bottles of paint required is ...
(22788.864 cm²)/(201 cm²/bottle) ≈ 113.4 bottles