Two sides of a triangle measure 4cm and 9cm. Determine which of the following choices cannot be the measure of the third side
The third side of a triangle must be less than the sum of the other two sides and greater than the difference of the other two sides.
In this case, the two sides given measure 4cm and 9cm.
So, the third side must be:
9cm - 4cm < third side < 9cm + 4cm
5cm < third side < 13cm
Therefore, a third side measurement of 2cm cannot be the measure of the third side, as it is not within the range of possible values.