SOLUTION: A building is 1 ft from a 9​-ft fence that surrounds the property. A worker wants to wash a window in the building 12 ft from the ground. He plans to place a ladder over the fenc

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: A building is 1 ft from a 9​-ft fence that surrounds the property. A worker wants to wash a window in the building 12 ft from the ground. He plans to place a ladder over the fenc      Log On


   

Question 1137366: A building is 1 ft from a 9​-ft fence that surrounds the property. A worker wants to wash a window in the building 12 ft from the ground. He plans to place a ladder over the fence so it rests against the building.​ (See the​ figure.) He decides he should place the ladder 7 ft from the fence for stability. To the nearest tenth of a​ foot, how long a ladder will he​ need?
Found 2 solutions by josgarithmetic, ikleyn:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Two similar triangles
smaller triangle ground leg 7, vertical leg 9
larger triangle ground leg 7+1=8, vertical leg 12

Ladder is hypotenuse of the larger triangle.
h%5E2=8%5E2%2B12%5E2
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Answer by ikleyn(52786) About Me  (Show Source):
You can put this solution on YOUR website!
.

To the reader: 

    The two right-angled triangles @josgarithmetics talks about in his solution are nor similar (!).


    Do not make this error together with @josgarithmetic (!)