bantu cari no 6 sama 7.. pake cara ya.. jangan langsung jawab saya gak tau caranya?

Bab Perbandingan
Matematika SMP Kelas VII

6] ST/QO = RT/OP
6/8 = RT/15
RT = 15 x 6 / 8
RT = 11,25 cm

✩✩ C ✩✩

7] AE/AC = DE/BC
16/(16 + CE) = 12/21
16 + CE = 21 x 16 / 12
CE = 28 - 16
CE = 12 cm

✩✩ D ✩✩