# Thread: can you help with a formula

1. ## can u help with a formula

(a) can be any length
(b) can be any width
(c) can be any angle

My starting point for this formula is (c) = 90 degrees

a d
. .
|
|
|
|
c---------b

if (c) was less than 90 or greater and i know than angle and know the sizes for (a) and (b)

What formula can i use to find the distance between a&d

hope u can help.

chees jimE

3. ## hi

just looked at my post (c) was in the wrong place please look again. What more do u need me t tell u about this question. i am very poor at maths and maybe i have not explained things right

cheers jim

4. ## can you help with a formula

A D
. .
. .
. .
......................
b C

A B Lenght 1500mm
D C length 1500mm

B C width 500mm

(Angle) A (B) C = 92 degrees (or any given angle)

(Angle) D (C) B = 92 degrees ( or any given angle)

Formula to work out distance between A & D

hope this helps more

jimE

5. Hello

You should use the tags [code] text of the "drawing" [/code] to "draw" otherwise the forum deletes the spaces when they are too numerous. (i.e. when there are more than two consecutive spaces)

Code:
A                    D
.                    .
.                    .
.                    .
......................
b                    C

6. Originally Posted by jime831
A D
. .
. .
. .
......................
b C

A B Lenght 1500mm
D C length 1500mm

B C width 500mm

(Angle) A (B) C = 92 degrees (or any given angle)

(Angle) D (C) B = 92 degrees ( or any given angle)

Formula to work out distance between A & D

hope this helps more

jimE

I've tried to draw what I think you have described. Turns out to be an isosceles trapezoid with base angles of 92 degrees and 88 degrees, respectively (total interior angle = 360 degrees in a quadralateral).

XY=500 since BY is parallel to CY, making BC = XY.

AX = DY since triangles ABX and DCY are congruent.

To find AX, use

$\displaystyle \cos 88 = \frac{AX}{1500}\Longrightarrow AX=1500 \cos88$

$\displaystyle AD=AX + XY + DY$

Substituting,

$\displaystyle AD=1500\cos88 + 500 + 1500\cos88\Longrightarrow500+3000\cos88\approx552. 3592$