37 sama 38 pakai cara ya pleaseeee

Bab Bangun Datar
Matematika SMP Kelas VII

37] belah ketupat
5x - 3 = 2x + 3
5x - 2x = 3 + 3
3x = 6
x = 6/3
x = 2

keliling = 4 . (2x + 3)
keliling = 4 . (2 . 2 + 3)
keliling = 4 . 7
keliling = 28 cm

38] persegi panjang
luas = p x l = 80
5a x 4a = 80
a² = 80 / 20
a = √4
a = 2

keliling = 2 x (p + l)
keliling = 2 x (5a + 4a)
keliling = 2 x 9a
keliling = 18 x 2
keliling = 36 m