Luas bangun gabungan tsb adalah...cm²

Luas gabungan
= (P x L) + (1/4 x πr2)
= (20 x 8) + (1/4 x 3.14 x 20^2)
= 160 + (1/4 x 3.14 x 400)
= 160 + (3.14 x 100)
= 160 + 314
= 474 cm2

semoga membantu :)