When constructing a triangle, it is important to remember that the "Triangle Inequality Theorem" holds. It states that the sum of the two sides of a triangle is always greater than the third side.
For #10, the two smaller sides are only 2 and 3 cm and their sum is only 5 cm. So it violates the Triangle Inequality Theorem.
In short, the triangle cannot be formed.
If you try to construct the triangle with the dimensions given in #10, you will basically form a line segment that is 5cm long.
For #10, you may write: "No triangle is formed, but the line segments overlap into one 5-cm line segment."