Jawaban:

37. 12 cm

38. 48 cm²

Penjelasan dengan langkah-langkah:

37.

PB dc = 16 cm

PB = a/360° × K. Lingkaran

PB dc = 80°/360° × 2.π.r

16 = 8/36 × 2.π.r

2 = 1/36 × 2.π.r

1 = 1/36 × π.r

36 = π.r

r = 36/π

PB = a/360° × K. Lingkaran

PB ba = 60°/360° × 2.π.r

PB ba = 1/6 × 2.π.36/π

PB ba = 1/6 . 2. 36

PB ba = 12 cm

38.

Lj aob = 36 cm²

Lj = a/360° × L. Lingkaran

Lj aob = a/360° × π.r²

36 = 60°/360° × π.r²

36 = 1/6 × π.r²

216 = π.r²

r² = 216/π

Lj = a/360° × L. Lingkaran

Lj doc = 80°/360° × π.r²

Lj doc = 8/36 × π. 216/π

Lj doc = 8/36 × 216

Lj doc =48 cm²