kak tolong bantu jawab no.7

Keliling= 1/2 lingkaran besar - 1/2 lingkaran kecil
=1/2×2πr - 1/2×2πr
=3,14×10-3,14×5
=31,4-15,7
=15,7cm

Luas= 1/2.πr²-1/2πr²
= 1/2×3,14.10.10-1/2×3,14.5.5
=157-78,5
=78,5 cm²

Maaf klo salah