Question

Given right triangle MNL what is the value of Cos(M)

Answer 1

Check the picture below

Answer 2

Step $1$

Find the value of MN

In the right triangle MNL

Applying the Pythagorean Theorem

$ML^{2} =MN^{2} +NL^{2}$

Solve for MN

$MN^{2}=ML^{2}-NL^{2}$

in this problem we have

$ML=25\ units\\NL=15\ units$

Substitute in the formula above

$MN^{2}=25^{2}-15^{2}$

$MN^{2}=400$

$MN=20\ units$

Step $2$

Find the value of cos (M)

we know that

In the right triangle MNL

$cos(M)=\frac{adjacent\ side\ angle\ M}{hypotenuse}=\frac{MN}{ML}=\frac{MN}{25}$

Substitute the value of MN

$cos (M)=\frac{20}{25}=\frac{4}{5}$

therefore

the answer is

The value of cos(M) is $\frac{4}{5}$