bantunya donk kakak hitz:v

Kesebangunan dan Kongruen

Sisi atas trapesium kecil
12/6+12 = a/15
12/18 = a/15
2/3 = a/15
2 x 15 = 3a
30 = 3a
a = 30/3
a = 10 cm

Alas trapesium besar
12/18 = 20/b
2/3 = 20/b
2b = 20 x 3
2b = 60
b = 60/2
b = 30 cm

L trapesium besar = 1/2 x jml sisi sejajar x t
= 1/2 (15 + 30) 18
= 45 x 9
= 405 cm^2

L trapesium kecil = 1/2 x jml sisi sejajar x t
= 1/2 (10 + 20) 12
= 30 x 6
= 180 cm^2

L arsiran = 405 - 180
= 225 cm^2

*semoga membantu. sukses selalu ^_^