lihat gambar!!! to long yh sma caranya no. 18,19,20 tlong sma caranya pliss

#18
= 1/3 x 314/100 x 10 x 10
= 1/3 x 314
= 314/3
= 104,666
= 104,67 cm²

#19
= 1/3 x 314/100 x 20
= 314/15
= 20,9333
= 20,8 cm

#20
= 1/4 x 22/7 x 7 x 7 - 1/2 x 7 x 7
= 154/4 - 24,5 cm²
= 38,5 cm² - 24,5 cm²
= 14 cm²

Maaf kalau salah