# Finding the slope of a line without coordinates or scale

• Aug 19th 2008, 11:28 AM
Kiki31
Finding the slope of a line without coordinates or scale
I've been trying to figure these questions out for hours, and I'm sure it's probably something very simple...

Here is the diagram I am working from...
http://img45.imageshack.us/img45/346/sc054dcc68ha6.jpg

What is the slope of AB?
If the measure of angle A=30 degrees, what is the slope of AB?
• Aug 19th 2008, 11:33 AM
topsquark
Quote:

Originally Posted by Kiki31
I've been trying to figure these questions out for hours, and I'm sure it's probably something very simple...

Here is the diagram I am working from...
http://img45.imageshack.us/img45/346/sc054dcc68ha6.jpg

What is the slope of AB?
If the measure of angle A=30 degrees, what is the slope of AB?

Slope is "rise over run" so the slope will be equal to a/b. Likewise you can use some simple trigonometry to prove that the slope is equal to $\displaystyle tan(\theta)$ where $\displaystyle \theta$ is angle A.

-Dan
• Aug 19th 2008, 11:37 AM
Kiki31
Okay, that's what I thought the first answer would be. Thanks :)

Any idea about the second question?
• Aug 19th 2008, 06:09 PM
topsquark
Quote:

Originally Posted by Kiki31
Okay, that's what I thought the first answer would be. Thanks :)

Any idea about the second question?

That's what the "tangent" comment was in reference to. The slope of the line is the tangent of angle A.

-Dan