tolong di jawab dong kak besok mau di kumpulin nomor 1 dan 2 aja

1.(7+14)x10/2
=21x5
=105cm²
2.31x16/2
=31x8
=248

1. 7cm+(7cmX2) = 7cm + 14cm=21cmX10cm=210cm:2=105cm²

2. 31cmX16cm=496:2=248cm²