Answer:
B, C
Step-by-step explanation:
to make a triangle the sum of lengths of any and every pair of sides must be longer than the third side. otherwise the end points cannot connect.
A
3+4<8 so, it cannot be a triangle.
B
7+6>12 true
7+12>6 true
6+12>7 true
C
5+11>13 true
5+13>11 true
13+11>5 true
D
4+6<12 so, it cannot be a triangle.
E
special case
4+6 = 10
but 4+6 is not longer than 10, so, all 3 lines would "fold" into one flat line. that does not count as triangle either, although I, personally, would consider it an "extreme triangle". but the general definition does not agree with me and requires the "longer than" condition.
