Finding base of triangle

[atanagy]

Hello,

This a question in a trades common core math book and I think there's not enough information to solve it. This is the exact question:

"A rectangular steel bar has a cross-sectional area of 468 mm2. The bar is to be reformed into triangular shaped bar with the same cross-sectional area. If the height of the triangle is 36 mm, what is the length of the base?"

 

[MarkFL]

For a triangle, we know:

[MATH]A=\frac{1}{2}bh[/MATH]
Solving this for the base \(b\), we obtain:

[MATH]b=\frac{2A}{h}[/MATH]
We are given the area \(A\) and the height \(h\), so it's now just a matter of plugging those in to obtain the base \(b\). what do you get?

 

[atanagy]

Thank you! The answer is 26 mm and it's correct! I wasn't sure how to apply the "cross-sectional area". The surface area of the steel bar or something similar written would have been less confusing. I also thought that the steel bar was going to be folded into a triangle. But it makes sense now. Thanks again!

 

[lev888]

Surface area and cross-sectional area are completely different things. Do you understand the difference?

 

[atanagy]

Yes, I do. Although, when I read the question, I was imagining a long steel bar that was going to be folded into a triangle. I was picturing the given area like a longer steel rod's cross-sectional area but rectangular.