kawan bantu saya no 7 donk

7. Keliling 1 = keliling persegi panjang = 2(p + l) = 2(18 + 7) = 2(25) = 50 cm
Keliling 2 = 2xkeliling 1/2 lingkaran = 2.1/2.2πr = 2πr
Kita pakai π = 22/7,
K2 = 2x22/7x7/2 = 22 cm
K(arsir) = K1 - K2 = 50 cm - 22 cm = 28 cm.