Step by step
The question
Question: can sides of 13, 6 and 6 make a triangle?
sides 13, 6, 6
For a triangle, the two short sides together must be longer than the longest side.
Else they cannot meet.
the two short sides must reach
round the longest one
1 Add the two short sides
The longest side is 13.
We lay it down first.
The two short sides are 6 and 6.
Together: 12.
= 6 + 6 = 12
2 Compare with the longest
Swing them up from the ends.
12 is less than 13: they do not even reach each other.
Careful!
Adding the long side to a short one is always enough.
The test is the two short sides.
Careful: add the two SHORT sides
So no: they cannot make a triangle.
= 12 < 13 → no triangle
3 Check
Let's check the other two pairs: 6 plus 13 is 19, and 6 plus 13 is 19.
Both are more than the third side.
So only the short pair decides.
So the answer is right!
6 + 13 = 19 > 6, 6 + 13 = 19 > 6
Let's look back.
First: add the two short sides.
Then: compare with the longest.
Last: check.
Answer
= 12 < 13 → no triangle