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# A fence 7ft tall runs parallel to a tall building at a distance of 4 ft from the building. What’s the length?

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A fence 7ft tall runs parallel to a tall building at a distance of 4 ft from the building. What’s the length of the shortest ladder that will reach from the ground over the fence to the wall of the building?

### 4 Answers

- goneLv 71 decade agoFavorite Answer
Get a scaffold, they don't make ladders big enough to be used by a human with that big a base. A2 + B2 = C2 doesn't work in this situation.

- 1 decade ago
Assuming you can't bend the ladder. . . (since this looks like a homework problem I am going to assume you can't.) A ladder 16' 1 1/2" would just barely be able to touch the building while missing the fence. (solve using pythagorean theorem)

- 1 decade ago
consider the following drawing: ignore the lines, they act as place holders.

___________/_|

________ n /__| building distance, d

=fence===/___|

______c_/ |___|

______ /7 |___| 7 ft

______ /__|4__|

have c be the distance of the ladder from the ground to the fence.

let n be the distance from above the fence, to the building.

for both these triangles, teh base is 4.

using the laws of similar triangles, you should get the answer.

use a system of equations to solve for the length.

- 1 decade ago
ummmm....ill go with 18ft??? unless your actually gonna try to climb this ladder?