What are the standard dimensions for paper size 297x210mm?

[chawki]

297-210
87mm.

 

[Mentallic]

I would interpret the question like that too, but then feel worried because that would be too simple. I'm confused as to what this question is asking exactly...

 

[chawki]

Yeah..I have same worry

 

[vela]

Are you sure one of the other edges isn't closer? I'd think that point will be closest to one of the long sides of the paper.

 

[chawki]

Can you please draw how you think it should be!

 

[osnarf]

You can't just assume that its 87, you need to know something about the other two lengths.

Daw a rectangle. Draw a diagonal through it. Draw 2 lines, perpendicular to each other and parallel to the sides, intersecting at a point on the diagonal.

so you should be looking at this: (see attached)

How do the two triangles relate? You need to try to find a relationship between a and b, and solve for them. Once you do that, compare their values to the known sides.

 

[chawki]

wow..ok the orange triangles have the same angle, but still can't find how to get a.

 

[chawki]

I think i get it.
Tan O = 297/210 = 1.414
O=54.73 degrees

Tan O = 87/a
a=87/tan O
a=87/1.414
a= 61.53mm ?

 

[osnarf]

D H: Sorry! Didn't mean to, like I said I was tired.

Chawki: Exactly, nicely done. You can do it in another simpler way, too, not involving any trig functions like tangent, sine, or cosine. Can you figure out how?

 

[chawki]

Nope Give me a small hint

 

[eumyang]

How about something named for a Greek mathematician?

 

[chawki]

ah yes Thales

a/210 = 87/297
a=61.51mm

 

[osnarf]

nicely done :)