PDA

View Full Version : Gcse maths


Nomad123
Dec 9, 2007, 09:30 AM
hey I'm in year ten and I'm doing higher maths
well I'm really stuck with this maths problem
I get to a certain point and then don't really understand what to do

a rectangle with sides

2x -1 and 3x-1

the length of the diagonal is the square root of 5

calculate the area of the triangle

I'm really stuck itd be great if I could have some help

:confused:

s_cianci
Dec 9, 2007, 09:41 AM
Draw and label the diagonal. Then apply the Pythagorean Theorem.

cool_dude
Dec 9, 2007, 09:43 AM
Area of triangle is
A= (bxh)/2 so it will be
A = (2x-1)(3x-1)/2

Now to solve this we must know what x is. To get x we use Pythagorean theorem which is
a^2 + b^2 = c^2
so you just plug in your lengths so it looks like
(2x-1)^2 + (3x-1)^2 = 5

Now solve for x and plug your x value into your area equation and your done.

Edit: s_cianci beat me by a minute lol

Nomad123
Dec 9, 2007, 10:56 AM
hey im in year ten and im doing higher maths
well im really stuck with this maths problem
i get to a certian point and then dont really understand what to do

a rectangle with sides

2x -1 and 3x-1

the length of the diagonal is the square root of 5

calculate the area of the triangle

im really stuck itd be great if i could have some help

:confused:
I got to the part of

(2x-1)^2 = (3x-1)^2 = 5

but I couldn't seem to solve it for x
I kept doing it wrng
and I don't no how to move on from there

cool_dude
Dec 9, 2007, 11:50 AM
Lol you didn't get to that part I told u that part and you didn't copy it down correctly. Its supposed to be:
(2x-1)^2 + (3x-1)^2 = 5

to solve for x just expandthe brackets and simplify and isolate for x. if you still can't do it then just show me how you expanded the brackets to see that at least your putting in some work instead of saying I can't do it.

katringette22
Dec 9, 2007, 11:53 AM
Expanted it all push the numbers to one side and letters to other and work grom there