No 23 tolong di bantu yah.. Pakai jalan

Luas
= Diagonal 1 × Diagonal 2 × 1/2
= ( 23 + 8 ) × ( 9 + 9 ) × 1/2
= 31 × 18 × 1/2
= 279 cm2

luas = 279 cm2
jadi jawabannya b
maaf kalao slah