Homework Yr 11 - Maths - Surds/Pythagoras Theorem *Help Please*

Hello Sythe Community,

Please help me with a question I am stuck on in my Maths Assignment. It would be greatly appreciated.

Explanation: In a rectangle, the diagonal is 3 times longer than the shorter side. Let the value of the shorter side be x. Hint, draw a sketch of a rectangle and its diagonal. Label the short side x, the diagonal 3x and the longer side "L".
Show your working out.

Question 7: Find the value of the longer side in terms of x and leave as a surd. Hint, use Pythagoras' Theorem.



A drawing on a piece of paper and then posting a response with an image showing exactly how you worked it out would be awesome. I'm stuck on what to do next with the Pythagoras' Theorem (Haven't done PT since Year 8) then how exactly to leave it as a surd.

Thanks alot!

 

i'm not sure if this is just a basic a^2+b^2=c^2 problem and i'm assuming surd is some uk name for radical or some shit. if so here is one way to solve it.


edit i used y for L but it doesn't really matter

i might have made my algebra a bit messy and i skipped factoring and shit too. i'll just put text here to show all steps

x^2+y^2=3^2x^2
x^2+y^2=9x^2
y^2=9x^2-x^2
y^2=x^2(9-1)
y^2=8x^2
y=sqrt(8x^2)
y=2xsqrt(2)

 

Hey man,

thanks, thats exactly what i'm looking for yeah, radical numbers or some shit it's called. She just calls it surds, is there anychance you can re-write it here; https://www.mathway.com/ and take a screenshot or some how type it, can't really see it too clear ;P

 

You sure that's right man, it seems way to confusing and hard for the first question of the this category. She normally makes the first one a little easy.

What I don't understand how the fuck you found out what 'x' is ('x' is the short hand side (left side)). It states that C is 3 times longer then 'x'. But I still don't understand how you worked out 'x' from just knowing that C is 3 times longer when you don't even know what Y/L is.

 

I didn't solve for x at all which is why it is in the final answer. All i did was isolate y or L on one side.

We know c is 3 times longer than x so c=3x.

knowing that all we have to do for a and b is use x and y and then put it all into our Pythagorean equation like this:

a^2 + b^2 = c^2

x^2 + y^2 = (3x)^2

see the resemblance?

Hope I helped, I'm off to bed.

 

This is fucking confusing

 

Is it the álgebra that is confusing or is it how i set it up?

 

I understand what you're doing it just can't be that fucking complicated. And like then the next question is;

b) Find the value of 'x' if the perimeter of the rectangle is 8. Answer as a surd.

Then on the next page (THE LAST PAGE) which is suppose to be hard, these so fucking easy. E.g;

8a) Using a calculator or otherwise, find the value of to 6 decimal places.

Like I get the highest marks out of the class in all our assignments/tests, how does she expect the other people in the class to do the question your trying to explain to me that I can't even do nor even think of how to get the answer without posting on a forum lol.

Can you add me on skype or something this just can't be lol.

 

Cyah.