Those segments can form a triangle because the two smallest sides, 7 and 8, add together to make 15, which is greater than the longest side, 12.
Yes.
12/21 = 4/7 in its simplest form.
12
A=0.5bhA=0.5*12*7A=42 ft2
7/12 is in its simplest form.
Yes they could.
Yes. What you should watch out for is that, to form a triangle, none of the segments should be longer (or as long as) the other two segments combined. Just check whether the longest segment is longer than the sum of the other two - if it is, then you can't form a triangle.
Yes.
true
Yes, they could.
No. In order for any three line segments to form a triangle, none of them can be greater in length than the sum of the other two.
yes
that's not a triangle
Yes and it will be in the form of an isosceles triangle having two equal sides.
Turn the 7 to form an angle with the other 7. It shapes a triangle.
Yes and it will be an isosceles triangle with 2 equal sides
12, 7, 7