Height of a building

• Jun 10th 2011, 02:51 PM
vaironxxrd
Height of a building
A girl wants to find the height of a building. She is standing 393 feet away from the building. There is a tree 42 in front of her, which she knows is 15 feet tall. How tall is the building?
My result is= \frac{42x}{42 } = \frac{5265}{ 42}= 125.357 or 125

http://img28.imageshack.us/img28/946...rybuilding.jpg
• Jun 10th 2011, 03:13 PM
Stro
Based on the information in the problem alone, the height of the building has little to do with the height of the tree. It could be 1200 ft, or 20 ft.

However this could be a similar triangle problem, with more information, in which case the drawing would look something more like:

http://i.imgur.com/6iRHP.jpg
• Jun 10th 2011, 03:19 PM
vaironxxrd
Quote:

Originally Posted by Stro
Based on the information in the problem alone, the height of the building has little to do with the height of the tree. It could be 1200 ft, or 20 ft.

However this could be a similar triangle problem, with more information, in which case the drawing would look something more like:

http://i.imgur.com/6iRHP.jpg

correct sorry for adding that I just did the distance of the building minus the distance to the tree.
• Jun 10th 2011, 03:27 PM
Stro
Quote:

A girl wants to find the height of a building. She is standing 393 feet away from the building. There is a tree 42 in front of her, which she knows is 15 feet tall. How tall is the building?
Can you post the exact wording for the problem you're working on? Based on the above there are multiple solutions.
• Jun 10th 2011, 03:40 PM
vaironxxrd
Quote:

Originally Posted by Stro
Can you post the exact wording for the problem you're working on? Based on the above there are multiple solutions.

yes I can. sorry I was trying to make it shorter but I notice that did not help.

"Ilse wants to find the height of the tallest building in her city. She stands 393 feet away from the building. There is a tree 42 feet in front of her. which she knows is 15 feet tall. How tall is the building ? ( Round to the nearest foot.)
• Jun 10th 2011, 03:54 PM
Stro
It's not your fault, the question is poorly worded. If your teacher doesn't often give "no solution" or "all real number" problems, then I'd assume this is a Similar Triangle problem, and the diagram I drew above is correct.

Solve for x:

$\frac{x}{15}= \frac{393}{42}$

However, if this were an ACT/SAT question, the answer would probably be something to the effect of "not enough information."
• Jun 10th 2011, 04:06 PM
bjhopper
How high is her eye?
• Jun 10th 2011, 04:16 PM
Stro
Quote:

How high is her eye?
It wouldn't matter unless you could somehow link the tree and the building (often done with shadows), or if you knew the angle of her eye line, I believe.
• Jun 10th 2011, 04:22 PM
vaironxxrd
Quote:

Originally Posted by Stro
It's not your fault, the question is poorly worded. If your teacher doesn't often give "no solution" or "all real number" problems, then I'd assume this is a Similar Triangle problem, and the diagram I drew above is correct.

Solve for x:

$\frac{x}{15}= \frac{393}{42}$

However, if this were an ACT/SAT question, the answer would probably be something to the effect of "not enough information."

140
• Jun 10th 2011, 04:23 PM
vaironxxrd
Quote:

Originally Posted by Stro
It's not your fault, the question is poorly worded. If your teacher doesn't often give "no solution" or "all real number" problems, then I'd assume this is a Similar Triangle problem, and the diagram I drew above is correct.

Solve for x:

$\frac{x}{15}= \frac{393}{42}$

However, if this were an ACT/SAT question, the answer would probably be something to the effect of "not enough information."

140
• Jun 10th 2011, 05:03 PM
Stro
Quote:

Originally Posted by vaironxxrd
140

Unless someone has a different take on this, I'd go with that answer for now (remember to write in your units). However, ask your teacher to explain the problem during office hours or study time.
• Jun 10th 2011, 05:25 PM
vaironxxrd
Quote:

Originally Posted by Stro
Unless someone has a different take on this, I'd go with that answer for now (remember to write in your units). However, ask your teacher to explain the problem during office hours or study time.

Thanks for the help , I will make sure of that