Answer :
Given:
In triangle MNO, angle ONM is a right angle. Angle NOM is 40 degrees and angle LMN is 50 degrees.
To find:
The value of cos(M).
Solution:
In a right angle triangle,
[tex]\cos \theta=\dfrac{Base}{Hypotenuse}[/tex]
Draw a diagram using the given information.
In triangle MNO, angle ONM is a right angle so its opposite side MO is the hypotenuse. For vertex M, MN is the base of the triangle. So,
[tex]\cos (M)=\dfrac{MN}{MO}[/tex]
Therefore, the correct option is B.
