SOLUTION: A light is to be mounted on the side of a building 18ft above the ground. The closest a ladder can be placed to the building is 6ft. To the nearest foot how long of a ladder will t

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: A light is to be mounted on the side of a building 18ft above the ground. The closest a ladder can be placed to the building is 6ft. To the nearest foot how long of a ladder will t      Log On


   

Question 747848: A light is to be mounted on the side of a building 18ft above the ground. The closest a ladder can be placed to the building is 6ft. To the nearest foot how long of a ladder will the electrician need so that he can mount the light?
Answer by Kg2003(10) About Me  (Show Source):
You can put this solution on YOUR website!
If you draw the picture, you will see that it is a right triangle you are solving for. To solve for the hypotenuse(the ladder in this case) you would use the Pythagorean theorem which is +a%5E2%2Bb%5E2=c%5E2+. When you substitute in your values you get +18%5E2%2B6%5E2=c%5E2+
Next simplify and get +324%2B36=c%5E2+. Simplify some more and now you have +360=c%5E2+ Square root both sides and do some rounding to get that the ladder is approximately 19 feet long.