Ada yg bisa bantu karmila ga?

Misal , lebar PQRS = x

Kesebangunan.

18/15 = 12/x
6/5 = 12/x
12/10 = 12/x
10 = x

Mencari keliling pqrs.
= 2(p + l)
= 2(15 + 10)
= 2(25)
= 50 cm.

semoga membantu..........