How do I work out this .....

Answer:
5.634
Step-by-step explanation:
First, you have to decide which one of the 6 trig functions you are going to use. Your calculator only gives 3 values (Sin,Cos,Tan) but the other three are easily figured out.
Each trig function has 3 variables, 2 of the three sides and 1 angle.
In this case, you want to adjacent side, and are given the hypotenuse. and the enclosed angle. That limits your choice to the cosine.
Cos(62) = adjacent / hypotenuse.
Cos 62 = 0.4695
hypotenuse = 12
0.4695 = adjacent / 12 Multiply both sides by 12
0.4695 * 12 = 12* adjacent/12
adjacent = 5.634
Answer:
This is right-angled trianle , so we will use trigonometry first.
[tex]sin(62^{\circ}) \approx 0,88[/tex]
Let AC=x , x>0
Then :
[tex]0,88=\frac{x}{12}[/tex]
[tex]0,88 \cdot 12=x[/tex]
[tex]x=10,56[/tex] cm
Now we obtain length of AB using Pytagoras' theorem :
Let AB=y
[tex](10,56)^{2}+y^{2} =12^{2}[/tex] , y>0
[tex]\frac{69696}{625}+y^{2} =144[/tex]
[tex]x=144-\frac{69696}{625} =\frac{20304}{625}=32,48[/tex] cm