Question

ABC is a triangle in which angle b is a right triangle, AB=1, AC=2, and BC = 3

Answer 1

This combination of sides is not possible. If angle B is 90 degrees, that means the side opposite to it should be the longest side. AB and BC are the legs of the right triangle, and AC is the hypotenuse. Since BC is longer than the hypotenuse AC, the triangle cannot exist.