Can 12, 5 and 8 make a triangle

Step by step

The question

Question: can sides of 12, 5 and 8 make a triangle?

For a triangle, the two short sides together must be longer than the longest side.

Else they cannot meet.

1 Add the two short sides

The longest side is 12.

We lay it down first.

The two short sides are 5 and 8.

Together: 13.

2 Compare with the longest

Swing them up from the ends.

13 is more than 12, so they meet at the top.

So yes: they make a triangle.

3 Check

Let's check the other two pairs: 5 plus 12 is 17, and 8 plus 12 is 20.

Both are more than the third side.

So only the short pair decides.

So the answer is right!

Let's look back.

First: add the two short sides.

Then: compare with the longest.

Last: check.