I think it's the second one on the top, because the dotted one is actually inside the bigger one and you can get a clear representation of the sizes.
Answer:
There is an error in the question.
All angles in an equilateral triange are 60º
3/x<span>÷5=1/10
3</span><span>÷5=1/10*x
6/10=1/10*x
6=x</span>
Answer: You basically have to 2xlw+2wh+2lh which means
2 multiplied by the length and width + 2 x the width and the height+ 2 x the length and height
Example:
l= 2
w=5
h=4
2x2x5+2x5x4+2x2x4
I hope this helps