Question

Two people are standing on opposite sides of a small river. One person is located at point Q, a distance of 25 meters from a bridge. The other person is standing on the southeast corner of the bridge at point P. The angle between the bridge and the line of sight from P is 72. 2 degrees. Use this information to determine the length of the bridge and the distance between the two people

Answer 1

69.56 meters

Explanation:

Let's call the distance between the two people "y" and the length of the bridge "x". Using trigonometry, we can set up two equations:

tan(72.2°) = y / 25

tan(90° - 72.2°) = y / x

We can simplify the second equation to:

tan(17.8°) = y / x

Now we have two equations with two unknowns. We can solve for one of the variables in terms of the other and substitute into the other equation to solve for the unknowns.

First, let's solve for y in the first equation:

tan(72.2°) = y / 25

y = 25 * tan(72.2°)

y ≈ 69.56 meters

Now we can substitute this value of y into the second equation:

tan(17.8°) = y / x

tan(17.8°) = 69.56 / x

x = 69.56 / tan(17.8°)

x ≈ 202.11 meters

Therefore, the length of the bridge is approximately 202.11 meters and the distance between the two people is approximately 69.56 meters.