The look-out point of a lighthouse is 50 feet above sea level. a woman observes a boat in the water from the look-out point. the angle of depression to the boat in the water is 20°. what is the distance from the base of the light house to the boat in the water?

137.4 feet

Step-by-step explanation:

Consider the attached diagram. The given angle of depression from the lighthouse to the boat is the same as the angle of elevation from the boat to the lighthouse. The trig relationship for tangent tells you ...

... tan(20°) = opposite/adjacent = AL/AB = 50'/AB

Solving for AB, we get

... AB = 50'/tan(20°) ≈ 50'/0.36397

... AB ≈ 137.4'

10% of increase is the final answer! : )

for the friend request.

when a figure, such as triangle (xyz) is reflected over the line y = x to create x'y'z' the x-coordinates and y-coordinates of the original image (pre-image) will be reversed for the image. (e.g., (x, y) > (y, x)) this means that the pre-image position of the x- and y-coordinates switch places which in turn provides a mirror like image of the original xyz.  

i notice that when i draw a line segment from x to x', that the points are parallel from each other -- they are exactly across from each other and do not intersect with any other points.  

yes, think i would see the same characteristic if you drew the line segment connecting y with the reflecting line and then y' with the reflecting line because of the essence of reflections. because it is a mirror image, each point was effected the same way which leads me to conclude that they same would apply to y and y'.