Could 12.2 cm 6.0 cm and 4.2 cm be the side lengths of a triangle

No.

Step-by-step explanation: No, as two of sides need to be equal.

we cannot form a triangle using the given lengths.

Step-by-step explanation:

There are three conditions that must be satisfied in order to form a triangle.

Let's take a, b and c are the sides of a triangle.

Conditions are:

i) a + b > c

ii) b + c > a

iii) c + a > b

Here let's take a = 12.2, b = 6.0 and c = 4.2

Let's check the conditions

i) 12.2 + 6 > 4.2

18.2 > 4.2

Which is true.

ii) 6 + 4.2 > 12.2

10.2 > 12.2

Which is not true.

The condition fails.

Therefore, we cannot form a triangle using the given lengths.

Hope this will helpful.

Thank you.

x= 149. 24+7=31. 180-31=149

your welcome