Jawab:
1. KUBUS
- Sisi (s) = 21 cm
- V = s x s x s
= 21 x 21 x 21
= 9.261 cm³
- Lp = 6 x (s x s)
= 6 x (21 x 21)
= 6 x 441
= 2.646 cm²
2. BALOK
- p = 16 cm, l = 8 cm, t = 6 cm
- V = p x l x t
= 16 x 8 x 6
= 768 cm³
- Lp = 2 x ((pxl) + (p x t) + (l x t))
= 2 x ((16 x 8) + (16 x 6) + (8 x 6))
= 2 x (128 + 96 + 48)
= 2 x 272
= 544 cm²
3. LINGKARAN
- d = 20 cm
- r = d : 2 = 20 : 2 = 10 cm
- π = 3,14
- L = π x r x r
= 3,14 x 10 x 10
= 314 cm²
- K = π x d
= 3,14 x 20
= 62,8 cm
4. LINGKARAN
- r = 21 cm
- π =
- L = π x r x r
= x 21 x 21
= 1.386 cm²
- K = 2 x π x r
= 2 x x 21
= 132 cm