∴ C= 180 -A-B= 75

sinC= sin75

= sin(30 +45)

= sin30 cos45 +sin45 cos30

= 1/2*√2/2+√2/2*√3/2

= (√2+√6)/4

According to sine theorem,

a/sinA= b/sinB= c/sinC

∴ 42/sin45 = b/sin60 = c/sin75

∴ b= 42/(√2/2)×√3/2= 2 1√6 (cm)

c = 42/(√2/2)×(√2+√6)/4 = 2 1+2 1√3(cm)

Therefore, c = 75, b=2 1√6cm, and c= 2 1+2 1√3cm.

I hope you can adopt it, but you can ask if you don't understand it. Thank you.