jawab menggunakan cara

DB=15cm
BC=20cm
Kel segi 3 ABCD
AD+AB+BC+DC=12+9+20+15=66(C)

AD = 12 cm
AB = 9cm
BC = ?
CD = 25 cm
BD = ?
BD² = 12²+9²
BD² = 144 + 81
BD² = 225
BD = √225
BD = 15


BC²= 25²-15²
BC²= 625 - 225
BC² = 400
BC = √400
BC = 20

keliling
AB + AD + DC + BC
9 + 12 + 25 + 20
66
C. 66