Answer:
Step-by-step explanation:
14.
altitude=√(8²-4²)=4√(2²-1²)=4√3
15.
x÷6=cos 60°
x=6×cos 60°=6×1/2=3
perimeter=18+6+(3+18+3)+6=54
16.
10√3÷PQ=sin 30°=1/2
PQ=20√3
10√3÷PR=sin 60°=√3÷2
PR=2×10√3÷√3=20
QR=√(20²+(20√3)²)
=√(400+1200)
=√1600
=40
perimeter=20+40+20√3=60+20√3
