# Cosine value

$\Delta GHI$

is a right angled triangle.

It is measured that

• Length of the opposite side
$\stackrel{‾}{GI}$

is

meters

• Length of the adjacent side
$\stackrel{‾}{HI}$

is

meters

• Length of the hypotenuse is
$\stackrel{‾}{HG}$

is

meters

• The angle of the triangle is

.

Now, calculate value of the cosine at angle

${30}^{°}$

by considering the length of the adjacent side and length of the hypotenuse.

The value of cosine at the angle

${30}^{°}$

is

$0.866$

for the triangle

$GHI$

.

$\Delta FED$

is another right angled triangle and it is measured that,

• The length of the opposite side
$\stackrel{‾}{DF}$

is

meters

• The length of the adjacent side
$\stackrel{‾}{EF}$

is

meters

• The length of the hypotenuse is
$\stackrel{‾}{ED}$

is

meters

• The angle of the triangle is

.

Repeat same procedure to calculate the value of cosine at an angle

${30}^{°}$

for the right angled triangle

$FED$

.