Jawaban:

1. luas alas = 22/7 × 7 × 7 = 154 cm²

luas selimut = 2 × 22/7 × 7 × 25 = 1.100 cm²

luas permukaan = 2(154) + 1.100 = 1.408 cm²

2. luas alas = 3,14 × 10 × 10 = 314 cm²

luas selimut = 2 × 3,14 × 10 × 8 = 504,2 cm²

luas permukaan = 2(314) + 504,2 = 1.132,2 cm²

3. luas alas = 3,14 × 5 × 5 = 78,5 cm²

luas selimut = 2 × 3,14 × 5 × 60 = 1.884 cm²

luas permukaan = 2(78,5) + 1.884 = 2.041 cm²

4. 4.224 = 2 (22/7 × 14 × 14) + 2 × 22/7 × 14 × t

4.224 = 1232 + 88t

2992 = 88t

t = 34 cm

5. 1.381,6 = 2 (3,14 × 10 × 10) + 2 × 3,14 × 10 × t

1.381,6 = 628 + 62,8t

753,6 = 62,8t

t = 12 cm