Tolong bantu y soalnya mau dibahas besok

Bangun Datar

L ∆ besar = 1/2 x a x t
= 1/2 x 12 x (6+9+7)
= 6 x 22
= 132 cm^2

L ∆ sedang = 1/2 x a x t
= 1/2 x 12 x (9+7)
= 6 x 16
= 96 cm^2

L ∆ kecil = 1/2 x a x t
= 1/2 x 12 x 7
= 6 x 7
= 42 cm^2

L arsiran = L ∆ besar + L ∆ sedang - L 2 ∆ kecil
= 132 + 96 - 2 x 42
= 228 - 84
= 144 cm^2 (B).

*semoga membantu. sukses selalu ^_^