Un gros rouleau de tissus de 3 m de large a une longueur de tissus totale de
14 dam.
Ce tissus se vend 1,26 $ le mètre carré.
Quelle est la valeur totale du rouleau de
tissus?

1. First, you must calculate the height (h) of the triangle, as below:
 
 Tan(α)=Opposite/Adjacent
 
 α=30º
 Opposite=16
 Adjacent=h
 
 2. When you substitute these values into Tan(α)=Opposite/Adjacent, you obtain:
 
 Tan(α)=Opposite/Adjacent
 Tan(30º)=16/h
 
 3. Now, you must clear "h":
 
 h(Tan(30º))=16
 h=16/Tan(30º)
 h=27.7
 
 4. The value of "x" is:
 
 Cos(β)=Adjacent/Hypotenuse
 
 β=41º
 Adjacent=h=27.7
 Hypotenuse=x
 
 5. When you substitute these values into Cos(β)=Adjacent/Hypotenuse, you have:
 
 Cos(β)=Adjacent/Hypotenuse
 Cos(41º)=27.7/x
 
 6. You must clear "x", as below:
 
 x(Cos(41º))=27.7
 x=27.7/Cos(41º)
 
 7. Therefore, the lenght "x" is:
 
 x=36.70