Jawaban:

1. luas alas = π×r²

= 22/7× 7²

= 22/7 ×49

= 22 cm

luas selimut = 2×π×r×t

= 2×22/7×7×25

= 44× 25

= 1.100 cm

luas permukaan = 2×π×r×(r+t)

= 2×22/7×7×(7+25)

= 2×22/7×7×32

= 44 ×32

=1.408 cm²

2. luas alas = 3,14 × 10²

= 3,14 × 100

= 314 cm

luas selimut = 2×π×r×t

=2×3,14×10×8

= 6,28 × 10× 8

= 62,8 × 8

= 502,4 cm

luas permukaan = 2×π×r×(r+t)

= 2×3,14×10×(10+8)

= 2×3,14×10×18

= 6,28×10×18

= 62,8 × 18

=1.130,4 cm²

3. luas alas = π×r²

= 3,14 × 5²

= 3,14 × 25

= 78,5 cm

luas selimut = 2×π×r×t

= 2×3,14×5×60

= 6,28 × 5× 60

= 31,4 × 60

= 1.884 cm

luas permukaan = 2×π×r×(r+t)

= 2×3,14×5×(5+60)

= 2×3,14×5×65

= 6,28×5×65

= 31,4 × 65

= 2.041 cm²

4. L = 2×π×r×t

4.224 = 2×22/7×14×t

4.224 = 2×22×2×t

4.224 = 44×2×t

4.224 = 88× t

t = 4.224 : 88

t = 48 cm

5. L = 2×π×r×t

1.381,6 = 2×3,14×10×t

1.381,6 = 6,28×10×t

1.381,6 = 62,8×t

t = 1.381,6 : 62,8

t = 22 cm

mohon maaf kalau salah