5. d = 40, r = 20

Luas lingkaran = πr² = 3,14 × 20² = 1.256 cm² × 50 (putaran) = 62.800 cm² = 628 m²

6. keliling lingkaran = 18,84 cm² = πd = 18,84 ÷ 3,14

d = 6

7. diameter maksimal = lebar persegi panjang = 21 cm

8.

Luas lingkaran = πr² = 3,14 × 3,5² = 3,14 × 12,25 = 38,465 cm²

Luas persegi = s² = 7² = 49 cm²

a. Total Luas = 38,465 + 49 = 87,465 cm²

Keliling persegi = 7+7 = 14

Keliling lingkaran = πd = 22/7 × 7 = 22

b. Total keliling = 14 + 22 = 36 cm

9. A. Keliling lingkaran = 2πr = 2 × 22/7 × 14 = 88 ÷ 4 (1/4 bagian) = 22 cm

B. Luas lingkaran = πr² = 22/7 × 14² = 616 ÷ 4 = 154 cm²

11. Luas persegi = s² = 14² = 196 cm²

Luas lingkaran = πr² = 22/7 × 7 × 7 = 154 cm²

total luas yang di arsir = 196 - 154 = 42 cm²

Semoga membantu >0<

~Trex