Pyramid question

Victor

Can you solve the attached question? State what level you are at (higher, lower, year).

Don't feel bad if you can't. Apparently its a difficult question.

Feral Mutant

Gottit. First year in college.

8*route13 or 28.844102

Why is this on the CTYI forum?

mathias

This is very basic ,

Area of a triangle = 1/2 base x perpendicular height ,

You already know the base is 4 , to get the height you use pythagoras for the right angle triangle in the centre ,

Square of the hypotenuse = sum of squares on other two sides , so thats

2 squared = 4 plus 3 squared = 9 = 13 , so hypotenuse = root 13 , this is the height of the triangle for a side.

Area of one side = 2 x root 13 , so 4 sides = 8 x root 13

PurpleFistMixer

Strange. I did it a slightly different way, I think. (I take this from the fact that your answer doesn't involve any roots of 17, and mine did.. : p)

But yes, same answer, so must have worked out alright.

And why shouldn't it be on the CTYI forum? : p It's not like the forum has any SPECIFIC purpose.

Victor

I've put the answer here: http://www.boards.ie/vbulletin/showpost.php?p=52221922&postcount=15

PFM, stop stalking me.

PurpleFistMixer

... No. I like pyramids.

Victor

Fairy nuff.

Same question.

Feral Mutant

Not enough information given. There's no way to determine the inclination of the side of length 3.

Garret

8 * route 13

1st year college, i remember doin that question last year

Victor

Feral Mutant wrote:

Not enough information given. There's no way to determine the inclination of the side of length 3.

Apologies. For a Feral Mutant you are very correct. Amended drawing attached.

PurpleFistMixer

Alright, I got 62.25 but it's highly likely I made a calculatory mistake along the way. I think my theory is alright, though I didn't use the 1 at all.

Feral Mutant

Victor wrote:

Apologies. For a Feral Mutant you are very correct. Amended drawing attached.

That's right. Everyone praise Daniel.
I got 8*route13 again.

Victor

Feral Mutant wrote:

That's right. Everyone praise Daniel.
I got 8*route13 again.

Oddly enough, yes. I should really work these out before posing them.

PFM: wrong! :shock:

Victor

Next one. Lets move on slightly.

PurpleFistMixer

Victor, where are you getting these from?

Victor

Oh, I'm just inventing them as I go along.