Yes.
12/21 = 4/7 in its simplest form.
12
A=0.5bhA=0.5*12*7A=42 ft2
To see if three lengths can be made into a triangle:Add together the two shorter lengths;if this sum is greater than the remaining length, then a triangle can be made;otherwise the sum is less than or equal to the remaining length and a triangle cannot be made.examples:3, 4, 53 + 4 = 7 > 5 ⇒ is a triangle 5, 5, 85 + 5 = 10 > 8 ⇒ is a triangle 12, 30, 1812 + 18 = 30 ≤ 30 ⇒ is not a triangle 12, 35, 1812 + 18 = 30 ≤ 35 ⇒ is not a triangle
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.
that's not a triangle
yes
Turn the 7 to form an angle with the other 7. It shapes a triangle.
Yes and it will be in the form of an isosceles triangle having two equal sides.
Yes and it will be an isosceles triangle with 2 equal sides
12, 7, 7