# Triangle Area

1. Feb 6, 2009

### keemosabi

1. The problem statement, all variables and given/known data
http://g.imagehost.org/view/0549/scan0001 [Broken]

Click the picture to get a larger, readable image.

I don't know where to start.

Last edited by a moderator: May 4, 2017
2. Feb 6, 2009

### Staff: Mentor

What is the formula for the area of a triangle, if one is given base and height?

Has one done the cross product of two vectors?

3. Feb 6, 2009

### keemosabi

(1/2)b*h

I haven't done the cross-product but it's preparation for the ACT, so there must be another way to do it.

4. Feb 6, 2009

### Staff: Mentor

Nevermind the cross-product. I was thinking that you had to find the area of the triangle. In future, please write out the problem statment in the post, rather than leaving it as a image.

Anyway, so we have A = 1/2 bh, as the area. Now if we take the line segment AB as the base, b, which is fixed, then what does h represent with respect to point C? And if the area, A, and base, b, remain constant, what does that imply about point C with respect to line segment AB?

5. Feb 6, 2009

### HallsofIvy

Staff Emeritus
Take AB as the base. As C moves, A and B stay fixed so b stays constant. In order that the area be constant, h must also be constant. That means C must move along a line parallel to AB.

6. Feb 6, 2009

### keemosabi

Alright, I get it now. Thank you both for the help.

Astronuc, sorry about that. I'll write out the question next time.