Thread: Help with formula please

Hi there,

Wondering if someone could help me out with formula to calculate 2 sides length of a 5 sided shape?

For the attached image I have the following dimensions:

A, B and C are all 700 mm

I need to calculate D and E where D = E

Would really appreciate it if someone could either provide a formula or explain how to structure the formula.

thanking you in advance.

Mark

The side of a square with diagonal d (here d = 700) is $\displaystyle \frac{d\sqrt{2}}{2}$.

Hi infoweb,
If you mean that A+B+C = 700mm there is no unique solution.There is no formula but you can calculate d by assuming A =a fraction of A and C another fraction of d.Express the total of the three sides in terms of d.Equate to 700mm

Hi there,

Thanks for the quick responses. It's been over 20 years since I've done any math like this so I'm totally out of touch!

@Bjhopper

Sorry, I didn't make my self clear enough:

A= 700
B= 700
C= 700

I now need to work out the length of E and D which should be equal to each other.

I tried the formula that emakarov provided but the answer I got didn't seem correct (494.97) not sure if that relates to the length of E and D as it seems too short.

Mark.

Originally Posted by infoweb

I tried the formula that emakarov provided but the answer I got didn't seem correct (494.97) not sure if that relates to the length of E and D as it seems too short.

$\displaystyle B\sqrt{2}/2$ gives you the side of the square whose diagonal is B. Thus, $\displaystyle D=A+B\sqrt{2}/2$.

Edit: This ignores the thickness of the segments.