Question 1182342
Addie says that the third side could be 9 cm. the other sides are 6 & 15 cm

The sum of the lengths of any two sides of a triangle must be greater than the third side. This Theorem is called the Triangle Inequality Theorem.

You cant draw a triangle because one of the options
6+9 is not greater than the third side 15

Drei is correct since it  follows the theorem