17 dan 18 !!! Pakai cara yah!

17)Luas tembereng O =56 :4 = 14 cm²
Luas tembereng O = (2/7) r²
14 cm² = 2/7 r²
r² = 14 x 7/2
r² =49
r. =√49
r = 7cm
Luas. O = π r²
= 22/7 x 7 x 7 = 154 cm² A


18) Luas 1 =sisi xsisi =10x10 =100cm²
Luas2 =π r² =3,14 x 5 x 5 = 78,5cm²
Luas ygdiarsir = 100 -78,5 = 21,5 cm²