assume that you have 3 different side lengths. apply the pythagorean theorem here: square each of the two shortest sides; call them a and b, so that their squares are a² and b². also square the longest side, calling the result c².
now, if a² + b² = c² is true, the triangle is a right triangle; otherwise it is not a right triangle.
The numbers on the first die are;
The numbers on the second die are;
The events of getting a sum of 5 are
There are four events.
The correct choice is B .