In the plane rectangular coordinate system, if the distance from point a (3, b) to the origin is 5, then the value of B is______ .

In the plane rectangular coordinate system, if the distance from point a (3, b) to the origin is 5, then the value of B is______ .

According to Pythagorean theorem: 32 + B 2 = 52, the solution: B = ± 4, so the answer is: ±