Answer:
{10m,21m,29m) can form a triangle
{10m,14m,29m) cannot form a triangle
{10m,29m,37m) can form a triangle
{10m,29m,40m) cannot form a triangle
Step-by-step explanation:
Triangles
A triangle is a three-sided plane figure. If a,b,c are its side lengths we must know how to recognize if a given triplet can be a proper set of sides
If a,b,c are meant to be the length of the sides of a triangle, there is a practical rule which can be used to tell if they are or not
"The sum of the two smaller sides must be greater than the biggest side"
If it's not true, for example, {5,7,14}, there is no way to arrange the smaller sides (5 and 7) to produce a triangle with 14 as the other side. It will simply won't connect with their endpoints. The greatest possible length they can form is 12, not enough to connect a side of length 14
With this rule in mind, we can easily tell:
{10m,21m,29m) can form a triangle since 31>29
{10m,14m,29m) cannot form a triangle since 24<29
{10m,29m,37m) can form a triangle since 39>37
{10m,29m,40m) cannot form a triangle since 39<40
