Question 1191760
the angle of depression of 15 forms a right triangle with the vertical leg of length 10 and the horizontal length of x + y.
tan(15) = 10 / (x + y)
solve for (x + y) to get:
(x + y) = 10 / tan(15) = 37.3205080


the angle of depression of 40 forms a right triangle with the vertical leg of 10 and the horizontal length of x.
tan(40) = 10 / x
solve for x to get:
x = 10 / tan(40) = 11.91753593.


y is equal to x + y minus x = 25.40297215.
that is the width of the river.


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theo