tolong di jwb no 1 dan 2 pliss pakai cara ya

AB/PQ = AC/PR = BC/QR
6/PQ = 12/18 = BC/15

6/PQ = 12/18
12PQ = 6 × 18
12PQ = 108
PQ = 108/12
PQ = 9

12/18 = BC/15
18BC = 12 × 15
18BC = 180
BC = 180/18
BC = 10

jawaban:
a. BC = 10
b. PQ = 9