To find the lengths of the sides, we will recall the trigonometric ratios for sine and cosine.
sin θ= Opposite/Hypotenuse, cos θ= Adjacent/HypotenuseIn our case, the angle is 25 ^(∘), the opposite side is y, the adjacent side is x, and the hypotenuse is 1.
sin 25 ^(∘)= y/1, cos 25 ^(∘)= x/1
We can rearrange these equations to get the equation for the length of each side.
x= cos ( 25 ^(∘))
y = sin ( 25 ^(∘))
To find their exact value we will use a calculator. Let's begin by making sure the calculator is in Degree mode. We do this by pushing MODE, selecting Degree instead of Radian in the third row, and pushing ENTER.
We are ready to go! We will push the COS button. After this we put in the value 25 and push the ENTER button. This will give us the value of cos 25^(∘).
The value of x is 0.9. We will do the same for y. This time, let's push the SIN button. After this, we will introduce the value 25 and push the ENTER button. This will show us the value of sin 25^(∘).
