berdasarkan gambar diatas, tentukan panjang sisi PQ dan QC!

pq / pc = ab / ac
pq / 4 = 9 / 6
pq = 9/6 x 4
pq = 6 cm

qc / pc = bc / ac
qc / 4 = (3+qc) / 6
4(3+qc) = 6qc
12 + 4qc = 6qc
6qc - 4qc = 12
2qc = 12
qc = 12/2
qc = 6 cm