Bagaimana cara mengerjakannya?

Bangun Datar

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

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

L segitiga B = 1/2 x a x t
= 1/2 x 12 x 7
= 6 x 7
= 42 cm^2

L arsiran = L segitiga BD + L segitiga BC - L 2 segitiga B
= 132 + 96 - 2 x 42
= 228 - 84
= 144 cm^2 (B).

*semoga membantu. sukses selalu ^_^