Check out the attached image for the drawing of how this would look. The drawing isn't 100% needed but it helps I think.
Based on the figure shown in the attachment, we have a right triangle with the adjacent leg of 80 (this leg is closest to the bottom 12 degree angle) and an opposite leg of h
In short,
adjacent = 80
opposite = h
We'll use the tangent rule
tan(angle) = opposite/adjacent
tan(12) = h/80
80*tan(12) = h
h = 80*tan(12)
h = 17.0045249336018 <<-- see note below
So the lighthouse is roughly 17.0045249336018 meters tall
Answer: 17.0045249336018
Note: Make sure you are in degree mode. The value is approximate. Round this answer however you need to
Based on the figure shown in the attachment, we have a right triangle with the adjacent leg of 80 (this leg is closest to the bottom 12 degree angle) and an opposite leg of h
In short,
adjacent = 80
opposite = h
We'll use the tangent rule
tan(angle) = opposite/adjacent
tan(12) = h/80
80*tan(12) = h
h = 80*tan(12)
h = 17.0045249336018 <<-- see note below
So the lighthouse is roughly 17.0045249336018 meters tall
Answer: 17.0045249336018
Note: Make sure you are in degree mode. The value is approximate. Round this answer however you need to