Question

How do I work out this .....

Answer 1

This is right-angled trianle , so we will use trigonometry first.

`sin(62^(\circ)) \approx 0,88`

Let AC=x , x>0

Then :

`0,88=(x)/(12)`

`0,88 \cdot 12=x`

`x=10,56` cm

Now we obtain length of AB using Pytagoras' theorem :

Let AB=y

`(10,56)^(2)+y^(2) =12^(2)` , y>0

`(69696)/(625)+y^(2)  =144`

`x=144-(69696)/(625) =(20304)/(625)=32,48` cm

Answer 2

5.634

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