Think of a big triangle drawn on the ground.
The shortest distance between two points is the straight line between them.
Therefore, it must be shorter for us to walk straight from one end of the longest
side to the other end of the longest side than it is to get there by walking
around the other two sides to get there.
So we add the smallest two numbers. If what we get is greater than the largest
number, then we have the sides of a triangle.
a) 5, 7, 10
The smaller two are 5 and 7, We add them and get 12. 12 is greater than
the remaining side, 10, so 5, 7 and 10 could be the sides of a triangle.
b) 12, 3, 14
The smaller two are 3 and 12, We add them and get 15. 15 is greater than
the remaining side, 14, so 12, 3 and 14 could be the sides of a triangle.
c) 5, 3, 1
The smaller two are 1 and 3, We add them and get 4. 4 is NOT greater than
the remaining side, 5, so 5, 3 and 1 could NOT be the sides of a triangle.
d) 7, 24, 25
The smaller two are 7 and 24, We add them and get 31. 31 is greater than
the remaining side, 25, so 7, 24 and 25 could be the sides of a triangle.
Edwin
