I need to put holiday lights on the windows of my house. I only have a 30 foot ladder, and the edge of the roof where I want to put the lights is 24ft. from the ground. How far away from the house should the base of the ladder be positioned so that the top of the ladder is exactly where the lights should be placed. Round to the answer to the nearest hundredth. Please draw and attach a picture to show all your work.

1 answer

To determine how far away from the house the base of the ladder should be positioned, we can use the Pythagorean theorem, which relates the lengths of the sides of a right triangle.

In this case:

  • The height from the ground to the edge of the roof is the vertical side of the triangle (24 feet).
  • The length of the ladder is the hypotenuse of the triangle (30 feet).
  • The distance from the base of the ladder to the house is the horizontal side of the triangle (which we need to find).

The Pythagorean theorem states:

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

Where:

  • \( a \) is the height (24 ft),
  • \( b \) is the distance from the base of the ladder to the house,
  • \( c \) is the length of the ladder (30 ft).

We can substitute the known values into the equation:

\[ 24^2 + b^2 = 30^2 \]

Calculating \( 24^2 \) and \( 30^2 \):

\[ 576 + b^2 = 900 \]

Now, subtract 576 from both sides:

\[ b^2 = 900 - 576 \] \[ b^2 = 324 \]

Now take the square root of both sides to solve for \( b \):

\[ b = \sqrt{324} = 18 \]

So the base of the ladder should be positioned 18 feet from the house.

Summary

  • Height to roof edge: 24 feet
  • Length of ladder: 30 feet
  • Distance from base of ladder to house: 18 feet

Unfortunately, I'm unable to draw and attach a picture, but you can visualize this as a right triangle:

  • The vertical leg (height) is 24 feet.
  • The hypotenuse (ladder) is 30 feet.
  • The horizontal leg (distance from the wall) is 18 feet.