Triangle 1 and triangle 2 are similar right triangles formed from a ladder leaning against a building.

Triangle 1 Triangle 2
The distance, along the ground, from the bottom of the ladder to the building is 18 feet. The distance from the bottom of the building to the point where the ladder is touching the building is 27 feet. The distance, along the ground, from the bottom of the ladder to the building is 10 feet. The distance from the bottom of the building to the point where the ladder is touching the building is unknown.

Determine the distance from the bottom of the building to the point where the ladder is touching the building for triangle 2.
6 feet
10 feet
15 feet
25 feet

1 answer

To find the distance from the bottom of the building to the point where the ladder is touching the building (let's call it \( h \) for triangle 2), we'll use the properties of similar triangles.

Given Triangle 1:

  • Distance along the ground (base) = 18 feet
  • Distance up the building (height) = 27 feet

For Triangle 2:

  • Distance along the ground (base) = 10 feet
  • Distance up the building (height) = \( h \) (unknown)

Since the triangles are similar, the ratios of corresponding sides are equal:

\[ \frac{\text{Base of Triangle 1}}{\text{Base of Triangle 2}} = \frac{\text{Height of Triangle 1}}{\text{Height of Triangle 2}} \]

Plugging in the values we have:

\[ \frac{18}{10} = \frac{27}{h} \]

Cross multiplying gives:

\[ 18h = 27 \cdot 10 \]

Calculating the right side:

\[ 18h = 270 \]

Now, solve for \( h \):

\[ h = \frac{270}{18} = 15 \]

Thus, the distance from the bottom of the building to the point where the ladder is touching the building for triangle 2 is:

\[ \boxed{15 \text{ feet}} \]