la 4 s'il vous plaît

1) ACB
ACB=180-(CAB+ABC)=180-(90+10)=180-100=80°
2) AC
tan(ABC)=tan(10°)=AC/AB=0.17632698
AC=AB×tan(10°)=88.16349035 ≈ 88.16 m
3) BC
cos(10°)=0.984807753=AB/BC
BC=AB/cos(10°)=507.7133059 ≈ 507.71 m
4) DB
cos(10°)=BH/DB
DB=BH/cos(10°)=406.1706448 ≈ 406.17 m
c'est tout !