Penjelasan dengan langkah-langkah:

1.

a. Keliling = π d

= 22/7 × 42

= 132 cm

Luas = π r²

= 22/7 × 21²

= 22/7 × 441

= 1.386 cm²

b. Keliling = π d

= 3,14 × 20

= 62,8 cm

Luas = π r²

= 3,14 × 10²

= 314 cm²

2.

a. Luas = π r²

616 = 22/7 × r²

616 × 7 = 22 × r²

4312 = 22 x r²

r² = 4312 ÷ 22

r² = 196

r = V196

= 14 cm

b. Keliling = π d

= 22/7 × 28

= 88 cm

3.

a. Keliling = 14 + (¼ π d) + (½ π d)

= 14 + (¼ × 22/7 × 28) + (½ × 22/7 × 14)

= 14 + 22 + 22

= 58 cm

Luas = (¼ π r²) - (½ π r²)

= (¼ × 22/7 × 14²) - (½ × 22/7 × 7²)

= (¼ × 22/7 × 196) - (½ × 22/7 × 49)

= 154 - 77

= 77 cm²

b. Keliling = 50 + 10 + 50 + (½ π d)

= 50 + 10 + 50 + (½ × 3,14 × 10)

= 50 + 10 + 50 + 15,7

= 125,7 cm

Luas = (p × l) + (½ π r²)

= (50 × 10) + (½ × 3,14 × 5²)

= (50 × 10) + (½ × 3,14 × 25)

= 500 + 39,25

= 539, 25 cm²