this is the problem v

http://oi57.tinypic.com/2uj4n61.jpg

it's in image form so you can see the diagram

Relevance
• 6 years ago

Why so urgent? Isn't geometry about timeless things like triangles? ;-)

But let's try it: Call RW "x", as it's easier to write, and we want to find it; and WS is then x+2.

And TW = 5.

There are three similar right triangles, do look and see, please: SRT, TRW, and STW, and you need to mind which angles and sides are corresponding, so you can use the ratios (same as proportions).

Ratios of corresponding sides, in two of the triangles:

x/5 = 5/(x+2) and so, very simply it rearranges into:

x(x+2) = 5*5 = 25 so you end up with:

x^2 + 2x - 25 = 0, a quadratic equation in standard from. Then you use the Quadratic Formula that you've learnt by heart (or can easily look up), and discover that:

x = [ -1 ± √(4 + 100) ] / 2

= (-1/2) ± (√104)/2 Quick, use a calculator, nearest tenth...

= (-1/2) ± (10.20/2)

= 5.10 - 0.5

= 4.60

I do hope all that's right, you might rather check it all (I would but have to leave in a hurry, sorry...)

And I hope it helps. :-)