Answer: 94
Step-by-step explanation:
3mm and 4mm and 5mm
This not the the traditional way but its pretty easy way to do it!
3 x 4 = 12
3 x 5 = 15
5 x 4 = 20
but before you add them up remember there are two of each so multiply all of them by 2
12 x 2 = 24
15 x 2 = 30
20 x 2 = 40
and now just add them up!
24 + 30 = 54
54 + 40 = 94
the reason i like this method is because all you have .to put on your paper is
12 ,15, 20
then you multiply by 2
and write 24, 30 ,40
and add them up! no weird formulas or any thing just simple logic