tolong di jawab...plis..

11. L. setengah lingkaran 1 = 1/2 × phi × r × r
=1/2 × 22/7 × 7 × 7
= 77
L.setengah lingkaran 2 = 77

L.stngh lingkaran 3 = 1/2 × phi × r × r
= 1/2 × 22/7 × 14 × 14
= 308
luas gab.= 77 + 77 + 308 = 462

12. L.segi tiga = 1/2 × a × t
= 1/2 × 20 × 8= 80

L.stngh lingkaran = 1/2 × phi × r × r
= 1/2 × 3,14 × 10 × 10
= 1/2 × 314
= 157

L.persegi = 20 × 20= 400

L= persegi - segitiga - stngh lingkaran
= 400 - 80 - 157
= 163 m