Here, two side lengths of a triangle given, 18 cm and 40 cm.
We know that, the sum of the lengths of any two sides of a triangle is greater that the third side.
So here, let's take the third side be x.
So we can write ,
Also we can write,
We will get x by subtracting 18 to both sides. We will get,
Also we can write,
As we know 40 >22, so it is obvious 40+x will be greater than 22, as x can not be negative.
So we will take the first two parts, we have got,
and
By using both of them, we can write,
So we have got the required answer. Possible length of the third side is .