terima kasih.
Jawaban:
[tex]3). \: \: keliling \: \frac{1}{4} \: lingkaran = \frac{1}{4} \times 2\pi \: r \\ = \frac{1}{4} \times 2 \times \frac{22}{7} \times 14 \\ = 22 \: cm \\ keliling \: bangun = 3 \times 14 + 22 \\ = 42 + 22 \\ = 64 \: cm[/tex]
[tex]4). \: \: keliling \: \frac{1}{2} \: lingkaran = \frac{1}{2} \times 2\pi \: r \\ = \frac{1}{2} \times 2 \times 3.14 \times 20 \\ = 62.8 \: cm \\ keliling \: bangun = 40 + 60 + 60 + 62.8 \\ = 222.8 \: cm[/tex]
3. Diketahui:
Sisi persegi (s) = 14 cm
jari-jari (s) = 14 cm
Maka keliling =
1/4 lingkaran + persegi =
(1/4)(2×π×s) + (4×s) =
(1/2)(π×s) + (4×s) =
s((1/2)π + 4) =
14×((1/2)×(22/7) + 4) =
14×((11/7) + 4) =
14×((11/7) + (28/7)) =
14×(39/7) =
2×39 =
78 cm ✔️
4. Diketahui:
p = 60, l = 40, d = 40
maka keliling =
2p + l + (1/2)π×d =
(2×60) + 40 + (1/2)×3,14×40 =
120 + 40 + 20×3,14 =
160 + 62,8 =
222,8 cm ✔️
