8.
cosA=AC/AB⇒AB=AC/cosA
cosA=√(1-sin²A)=√(1-0.64)=√0.36=0.6
AB=18/0.6=30
BC=√(AB²-AC²)=√(30²-18²)=√(900-324)=√576=24
sinA=CC1/AC⇒CC1=AC*sinA=18*0.8=14.4
AC1=√(AC²-CC1²)=√(18²-14.4²)=√(324-207.36)=√116.64=10.8
BC1=√(BC²-CC1²)=√(24²-14.4²)=√(576-207.36)=√368.64=19.2