The quastion is asking us to determine the measure of angle M in a right triangle LMN. We know that angle N is a right angle and that LM = 76 ( Hypotenuse ) and MN = 40 ( Adjacent ). We will use trigonometry: cos M = Adjacent / Hypotenuse = 40 / 76 = 0.5263158; M = cos^(-1) 0.563158; M = 58.242° = 58° 15`. Answer: The measure of angle M is<span> 58°15`.</span>
Notice that
, so
Then taking the positive square root gives
so 
and 
.
Perpendicular: slope is -3/2
Based on this I would already know the answer is A.
