Nomor 31 tolong dibantu yaa

PQ² = AB² – (r1 – r2)²
AB² = PQ² + (r1 – r2)²
AB² = 225 + (12-4)²
AB² = 225 + 64
AB = √289
AB = 17 cm

Pq = akar abkuadrat – (r1 – r2)kuadrat
225 = abkuadrat – 64
abkuadrat = 289
ab = 17