tolong di jawab yaa beserta cara penyelesainnyaaa...

10/12 = a/18
a = 18 x 10/12
a = 15 cm


21/18 = b/12
b = 12 x 21/18
b = 14 cm

9/18 = c/12
c = 12 x 9/18
c = 6 cm