How far is it from the lighthouse to the ship horizontally if the lighthouse is 20 ft tall and shines a beam to the ship 25 ft long?

Also, which statement is correct?

(1 point)
Responses

x = approximately 24.5 yards; from the top of the lighthouse to the boat must be the shortest distance
x = approximately 24.5 yards; from the top of the lighthouse to the boat must be the shortest distance

x = 15 ft; the distance from the top of the lighthouse to the ship must be the longest distance
x = 15 ft; the distance from the top of the lighthouse to the ship must be the longest distance

x = 15 ft; the distance from the lighthouse to the ship must be the shortest distance
x = 15 ft; the distance from the lighthouse to the ship must be the shortest distance

x = 225 feet; the distance from the lighthouse to the ship must be the longest distance

1 answer

To find the horizontal distance from the lighthouse to the ship, we can use the Pythagorean theorem. We have a right triangle where:

  • One leg (height of the lighthouse) = 20 ft
  • The other leg (horizontal distance) = x (unknown)
  • Hypotenuse (length of the beam) = 25 ft

According to the Pythagorean theorem:

\[ a^2 + b^2 = c^2 \]

Substituting in the values we know:

\[ 20^2 + x^2 = 25^2 \]

Calculating the squares:

\[ 400 + x^2 = 625 \]

Now, subtract 400 from both sides:

\[ x^2 = 625 - 400 \] \[ x^2 = 225 \]

Taking the square root of both sides:

\[ x = \sqrt{225} = 15 \text{ ft} \]

So the horizontal distance from the lighthouse to the ship is 15 ft.

Now, let's evaluate the statements given:

  1. x = approximately 24.5 yards; from the top of the lighthouse to the boat must be the shortest distance - This is incorrect.

  2. x = 15 ft; the distance from the top of the lighthouse to the ship must be the longest distance - This is correct; the distance from the top of the lighthouse (the hypotenuse) to the ship is longer than the horizontal distance (15 ft).

  3. x = 15 ft; the distance from the lighthouse to the ship must be the shortest distance - This is incorrect in the context of comparing distances (the beam's length is longer).

  4. x = 225 feet; the distance from the lighthouse to the ship must be the longest distance - This is incorrect; the distance is 15 ft, not 225 ft.

Correct statement:

  • x = 15 ft; the distance from the top of the lighthouse to the ship must be the longest distance (second option).