Originally Posted by

**technics** dont get it....

That's unfortunate...

Alright if you had a rectangle with a side of 5, you would say the opposite side is 5.

now look at the rectangle-like thing.

Code:

26.2
_____________________
| |
| |
|a |19.5
| |
| b 2 |
----------------:____|
9.6

now we can look at the side that says 26.2 and conclude that $\displaystyle b+9.6=26.2$

Code:

26.2
_____________________
| |
| |
|a |19.5
| |
| b 2 |
----------------:____|
9.6
:---------26.2-------:

Now if $\displaystyle b+9.6=26.2$ than of course $\displaystyle b=26.2-9.6=16.6$

can you do side a?