Given:
The base of the given triangle has two part:
Left( left side of the hypotenuse) = 25
Right ( right side of the hypotenuse) = x
The altitude (h) = 60
To find the value of x.
Formula:
By Altitude rule we know that, the altitude of a triangle is mean proportional between the right and left part of the hypotenuse,
Now,
Putting,
left = 25, altitude = 60 and right = x we get,
or, [ by cross multiplication]
or,
or,
Hence,
The value of x is 144.
The answer is:
The correct option is:
D. 40 feet.
<h2>Why?</h2>To solve the problem and calculate the width of the river, we need to assume that the distance from A to B and the angle formed between that distance and the distance from A to the other point (C) is equal to 90°, meaning that we are working with a right triangle, also, we need to use the given angle which is equal to 34°. So, to solve the problem we can use the following trigonometric relation:
Where,
alpha is the given angle, 34°
Adjacent is the distance from A to B, which is equal to 60 feet.
Opposite is the distance from A to C which is also equal to the width of the river.
So, substituting and calculating we have:
Hence, we have that the correct option is:
D. 40 feet.
Have a nice day!